How to achieve aonther's IP address from Yahoo messenger?

Only Yahoo's servers know that, and they're not going to tell you. I can't think of any *legitimate* reason why you would need to know this.

If you want the IP because of a profane or other unacceptable message, your best bet is to contact Yahoo.

according to  DVation191 , but when  you chat whit severral person, you can't know exactly who you want to acheive IP address

simply chatting with somebody, you cannot see their ip using that command. only if you connect directly to them will you be able to see that...so unless you are connected to more than one person directly, it wont work.

You would have to ask them to tell you what their IP address is--Yahoo messenger can not give you that information. If they send you email you can see what their IP is, but remember that in many cases IP addresses are changed so what a person is using today or this hour may be someone elses tomorrow.

If you explain what you are trying to do, one of us can possibly help you determine the information you need to know.

Because when i'm on Net, sometimes , my friends chat with me with strange nick! anh she or her don't talk to me who she/he is or where she/he is! I want to know her/his IP to chat with person has the same IP with my friend , so i can know where she/he is, and guess who she/he is

maybe you should just diable accepting messages from unknown people