psftp binary size is about to 300K and I need a smaller one. anyone suggests any idea?

Try vsftpd - from quick look at the documentation, it seems to be smaller than 300K and still offers a secure ftp.
Note, I have never used it so I don't know if this is what you want or not.

gonna try it and tell u about the result, thx for suggestion.

in fact I was searching for a client

I couldn't find any other one, and gonna try porting open ssh to an ftp client. I will inform you about the results.