Thanx a lot my friend Kolok,
I changed it in smarty only coz is next block it throw some problems and that why my site is not seams like in proper look... & third option is also says that "To use Memcached, you must to install the Memcache PECL extension on your server."
But any way i'm happy to see that my sites loading time really increased from 999.000 second(s) (0.000 s/Kb) to 17.686 second(s) (2.842 s/Kb)....
thanx again.....