diff --git a/libgrive/src/drive/Resource.cc b/libgrive/src/drive/Resource.cc
index ae531fb..143aea2 100644
--- a/libgrive/src/drive/Resource.cc
+++ b/libgrive/src/drive/Resource.cc
@@ -102,13 +102,32 @@ Resource::Resource( const fs::path& path ) :
 /// Update the state according to information (i.e. Entry) from remote. This function
 /// compares the modification time and checksum of both copies and determine which
 /// one is newer.
-void Resource::FromRemote( const Entry& remote )
+void Resource::FromRemote( const Entry& remote, const DateTime& last_sync )
 {
-	// sync folder is easy
+	fs::path path = Path() ;
+	
+	// sync folder
 	if ( remote.Kind() == "folder" && IsFolder() )
 	{
-		Log( "folder %1% is in sync", Name(), log::verbose ) ;
-		m_state = sync ;
+		// already sync
+		if ( fs::is_directory( path ) )
+		{
+			Log( "folder %1% is in sync", path, log::verbose ) ;
+			m_state = sync ;
+		}
+		
+		// remote file created after last sync, so remote is newer
+		else if ( remote.MTime() > last_sync )
+		{
+			Log( "creating %1% directory", path, log::info ) ;
+			fs::create_directories( path ) ;
+			m_state = sync ;
+		}
+		else
+		{
+			Trace( "should I delete the local directory %1%?", path ) ;
+			m_state = local_deleted ;
+		}
 	}
 	
 	// if checksum is equal, no need to compare the mtime
@@ -118,17 +137,32 @@ void Resource::FromRemote( const Entry& remote )
 		m_state = sync ;
 	}
 	
+	// local not exists
+	else if ( !fs::exists( path ) )
+	{
+		if ( remote.MTime() > last_sync )
+		{
+			Trace( "new file found in remote", path ) ;
+			m_state = remote_new ;
+		}
+		else
+		{
+			Trace( "should I delete the local file %1%?", path ) ;
+			m_state = local_deleted ;
+		}
+	}
+	
 	// use mtime to check which one is more recent
 	else
 	{
-		assert( m_state == local_new || m_state == local_changed || m_state == local_deleted ) ;
+		assert( m_state == local_new || m_state == local_changed || m_state == remote_deleted ) ;
 
 		// if remote is modified
 		if ( remote.MTime() > m_entry.MTime() )
 			m_state = remote_changed ;
 		
 		// remote also has the file, so it's not new in local
-		else if ( m_state == local_new || m_state == local_deleted )
+		else if ( m_state == local_new || m_state == remote_deleted )
 			m_state = local_changed ;
 		
 		Log( "%1% state is %2%", Name(), m_state, log::verbose ) ;
@@ -150,9 +184,11 @@ void Resource::FromLocal( const DateTime& last_sync )
 	
 	else
 	{
-		// assume file is local_deleted?? very strange. change it tomorrow
+		// if the file is not created after last sync, assume file is
+		// remote_deleted first, it will be updated to sync/remote_changed
+		// in FromRemote()
 		DateTime mtime = os::FileMTime( path ) ;
-		m_state = ( mtime > last_sync ? local_new : local_deleted ) ;
+		m_state = ( mtime > last_sync ? local_new : remote_deleted ) ;
 		
 		Log( "%1% found on disk: %2%", Name(), m_state ) ;
 	}
@@ -275,6 +311,10 @@ void Resource::Sync( http::Agent *http, const http::Headers& auth )
 		m_state = sync ;
 		break ;
 	
+	case remote_deleted :
+		Log( "sync %1% deleted in remote. delete?", Path(), log::verbose ) ;
+		break ;
+	
 	case sync :
 		Log( "sync %1% already in sync", Path(), log::verbose ) ;
 		break ;
@@ -448,7 +488,8 @@ std::ostream& operator<<( std::ostream& os, Resource::State s )
 {
 	static const char *state[] =
 	{
-		"sync",	"local_new", "local_changed", "local_deleted", "remote_new", "remote_changed"
+		"sync",	"local_new", "local_changed", "local_deleted", "remote_new",
+		"remote_changed", "remote_deleted"
 	} ;
 	assert( s >= 0 && s < Count(state) ) ;
 	return os << state[s] ;
diff --git a/libgrive/src/drive/Resource.hh b/libgrive/src/drive/Resource.hh
index aad5c01..25b2299 100644
--- a/libgrive/src/drive/Resource.hh
+++ b/libgrive/src/drive/Resource.hh
@@ -71,7 +71,7 @@ public :
 	bool IsInRootTree() const ;
 	bool IsRoot() const ;
 
-	void FromRemote( const Entry& e ) ;
+	void FromRemote( const Entry& remote, const DateTime& last_sync ) ;
 	void FromLocal( const DateTime& last_sync ) ;
 	
 	void Sync( http::Agent *http, const http::Headers& auth ) ;
diff --git a/libgrive/src/drive/ResourceTree.cc b/libgrive/src/drive/ResourceTree.cc
index 2dfc88f..0523ce3 100644
--- a/libgrive/src/drive/ResourceTree.cc
+++ b/libgrive/src/drive/ResourceTree.cc
@@ -160,11 +160,11 @@ void ResourceTree::Erase( Resource *coll )
 	s.erase( s.find( coll ) ) ;
 }
 
-void ResourceTree::Update( Resource *coll, const Entry& e )
+void ResourceTree::Update( Resource *coll, const Entry& e, const DateTime& last_sync )
 {
 	assert( coll != 0 ) ;
 
-	coll->FromRemote( e ) ;
+	coll->FromRemote( e, last_sync ) ;
 	ReInsert( coll ) ;
 }
 
@@ -177,33 +177,5 @@ ResourceTree::iterator ResourceTree::end()
 {
 	return m_set.get<ByIdentity>().end() ;
 }
-/*
-void ResourceTree::Read( const Json& json )
-{
-	Clear() ;
-	
-	assert( m_root == 0 ) ;
-	m_root = new Resource ;
-	AddTree( m_root, json ) ;
-}
 
-void ResourceTree::AddTree( Resource *node, const Json& json )
-{
-	assert( node != 0 ) ;
-	m_set.insert( node ) ;
-	
-	std::vector<Json> array = json["child"].AsArray() ;
-	for ( std::vector<Json>::iterator i = array.begin() ; i != array.end() ; ++i )
-	{
-		Resource *c = new Resource( *i, node ) ;
-		node->AddChild( c ) ;
-		AddTree( c, *i ) ;
-	}
-}
-
-Json ResourceTree::Serialize() const
-{
-	return m_root->Serialize() ;
-}
-*/
 } // end of namespace
diff --git a/libgrive/src/drive/ResourceTree.hh b/libgrive/src/drive/ResourceTree.hh
index 9484565..b7a2344 100644
--- a/libgrive/src/drive/ResourceTree.hh
+++ b/libgrive/src/drive/ResourceTree.hh
@@ -81,7 +81,7 @@ public :
 	
 	void Insert( Resource *coll ) ;
 	void Erase( Resource *coll ) ;
-	void Update( Resource *coll, const Entry& e ) ;
+	void Update( Resource *coll, const Entry& e, const DateTime& last_sync ) ;
 	
 	Resource* Root() ;
 	const Resource* Root() const ;
@@ -89,12 +89,8 @@ public :
 	iterator begin() ;
 	iterator end() ;
 
-// 	void Read( const Json& json ) ;
-// 	Json Serialize() const ;
-
 private :
 	void Clear() ;
-// 	void AddTree( Resource *node, const Json& json ) ;
 
 private :
 	details::Folders	m_set ;
diff --git a/libgrive/src/drive/State.cc b/libgrive/src/drive/State.cc
index d17bb99..3a8234e 100644
--- a/libgrive/src/drive/State.cc
+++ b/libgrive/src/drive/State.cc
@@ -128,7 +128,7 @@ bool State::Update( const Entry& e )
 	
 	if ( Resource *res = m_res.FindByHref( e.SelfHref() ) )
 	{
-		m_res.Update( res, e ) ;
+		m_res.Update( res, e, m_last_sync ) ;
 		return true ;
 	}
 	else if ( Resource *parent = m_res.FindByHref( e.ParentHref() ) )
@@ -141,31 +141,17 @@ bool State::Update( const Entry& e )
 		if ( child != 0 )
 		{
 			// since we are updating the ID and Href, we need to remove it and re-add it.
-			m_res.Update( child, e ) ;
+			m_res.Update( child, e, m_last_sync ) ;
 		}
 		
 		// folder entry exist in google drive, but not local. we should create
 		// the directory
 		else if ( e.Kind() == "folder" || !e.Filename().empty() )
 		{
-			// TODO: compare the last sync time to determine which one is newer
-			if ( e.MTime() > m_last_sync )
-			{
-				child = new Resource( e ) ;
-				parent->AddChild( child ) ;
-				m_res.Insert( child ) ;
-				
-				fs::path child_path = child->Path() ;
-				if ( child->IsFolder() && !fs::is_directory( child_path ) )
-				{
-					Log( "creating %1% directory", child_path, log::info ) ;
-					fs::create_directories( child_path ) ;
-				}
-			}
-			else
-			{
-				Trace( "should I delete the local %1%/%2%", parent->Path(), e.Filename() ) ;
-			}
+			child = new Resource( e ) ;
+			parent->AddChild( child ) ;
+			m_res.Insert( child ) ;
+			m_res.Update( child, e, m_last_sync ) ;
 		}
 		else
 		{