Thanks for your reply.
It still does not function with Encoding.GetEncoding("GB2312")、Encoding.GetEncoding("GBK")、Encoding.GetEncoding("Big5")。
My test programme is simple,like this:
ftpConnection1.DataEncoding = Encoding.GetEncoding("GB2312");
ftpConnection1.Connect();
string[] files = ftpConnection1.GetFiles();
listBox1.Items.AddRange(files);
ftpConnection1.Close();
it returns result but all Chinese character is disappeared.