AssetDatabase.CreateFolder
static function CreateFolder(parentFolder: string, newFolderName: string): string;
static string CreateFolder(string parentFolder, string newFolderName);
static def CreateFolder(parentFolder as string, newFolderName as string) as string
Parameters

parentFolder The name of the parent folder.
newFolderName The name of the new folder.
Returns
string The GUID of the newly created folder.
Description

Create a new folder.

		string guid = AssetDatabase.CreateFolder("Assets", "My Folder");
		string newFolderPath = AssetDatabase.GUIDToAssetPath(guid);