Is it possible to prevent emacs auto saving the filename~?

[明覺 <shi.minjue@gmail.com>]

I know that emacs auto save a file named filename~ when I modified the
file filename, but I do not like the autosaved copy, could i stop this
function? thanks

-- 
My platform is Gnu/Linux Debian(sid-amd64, lenny-intelx86) Gnome
Mozilla/Iceweasel Gmail/Evolution Gtkmm/Anjuta/Emacs Scim Totem
Pidgin.