Thanx makopo , this is really what i wanted .. so finally watashi is used to teach ..

They both have the same meaning ^-^ Watashi is a formal(polite) way. Atashi is a casual way. I usually use Atashi. But I use Watashi serious place. Men who use it are not many. the prime minister and politicians use it^0^/

If you talk with your friends, you'd better refer yourself ORE. But if you are in job searching, getting an interview or talking with the professors, you'd better say yourself Watashi. Watashi wa takeshi desu: QUITE allright! And it is most natural!

thnx RYO to answer me .. but i still can't understand .. THIS IS WHAT I WANT if a normal (not business , not director ) man use watashi , is it girlish and people in japan will laugh on you ? because when learning from books i find watashi , so a normal man can use it ?

Women usually use both "watashi"and"atashi", and it make no difference. But younger people like to call herself "atashi". I feel that ladies tend to use former ,and girls tend to use later. Man usually call himself "boku"and"ore". But in official situation like his business, they had better use "watashi". So man also often use "watashi".