我认为您需要检查IIS用户是否有权在该文件夹上写.

您应该向用户提供写访问权限.或检查
http://blogs.msdn.com/david.wang/archive/2005/08/20/Why-can-I-upload-a-file-without-IIS-Write-Permission.aspx

I think you need to check if IIS user has permission to write on the folder.

You should provide write access to the user. Or check
http://blogs.msdn.com/david.wang/archive/2005/08/20/Why-can-I-upload-a-file-without-IIS-Write-Permission.aspx