How to large file send to ftp using c# .net windows application?

Have you tested with any samples. I suggest you to create few samples and test.
Here is a good starting point ...
 
http://msdn.microsoft.com/en-us/library/ms229715(v=vs.90).aspx[^]
 
There should not be any problems in uploading large files if you input and output streams are correct. FTP uses TCP transport layer to send data which will remain open day or event week. So the size and time will not be an issue.