Everyday my friend gambles with his money as same with his life and he always gambling throwing away his money for nothing but losing and the worth part of it is he owes me money 
In your friends case, no gambling is not worth playing, and it sounds like an addiction so he should seek help for his addiction; not paying you back is a problem. However, gambling can be worth playing for fun and recreation, provided you have self control and set your limits.
really? addicted is that so >.< how i can help him with that addiction? i tried to tell him about how can gambling game ruin your life he just told me to mind my own business -_- so i got sad for that moment because his my best friend i can't see him being poor and lonely his girl friend leaved him for not noticing his girl friend he even calculates the gambling game -_- i might say his going to be a creepy guy one day he always say's to me that i can be a good gambler because i helped him once and won but its my money dough but still its i asked him get a doctor or something to cure that addiction