Are you sending the data as binary or text?
Did you define the mainframe file as fixed or variable?
Have you verfified the data is valid on the PC?
What FTP options are you using in your transfer?
Basically, all you are telling us is that your process didn't work. If you want help, you're going to have to provide a lot more data. In general, you are getting one line on the mainframe because the FTP process is not recognizing line terminators. A Windows system typically uses carriage return / line feed (CR/LF or CRLF) to end a line of text. A Unix system typically uses a line feed (LF) to end a line of text. Mainframes don't use line terminators since they are record-oriented. Depending upon where the file was generated, how it got to the Windows machine, and the encoding of the file on the PC (ASCII? UTF-8? UTF-16? something else entirely?) it may or may not be possible to transfer the file to the mainframe in a recognizable format.