I''m a beginner of Winsock, I don''t know much about it. My question is how to send data to a specific TCP port by Winsock? In my case, the receiving side is not using Winsock to receive it. Can winsock work in this situation?

You have to create a connection between the two computers. This means one must be ''listening'' to a port, so that another computer can connect to it. Different socket implementations (BSD sockets, WinSock etc.) should be compatible with each other, as they are all implementing the same protocol, and are just sending streams of bytes, so as long as the other computer is using a socket implementation it should work fine.