How do I file child abandonment if we're not in the United States of America but my child is a legitimate American citizen? She acquired citizenship at birth because her father applied for it and she has been given the Consular Report of Birth Abroad plus her own US passport.
Her father disappeared about a year ago. He never contact me or anything, he just simply disappeared and I want my child to have some support from him since she will start preschool this year.

You file an action to require the father to pay child support. I see that you and the child do not live in the United States. Child support is not a matter of U.S. federal law, so you cannot sue in Federal court. You probably would have to file in the country where you are located. What country is it in which you live?

Unless abandonment is a crime where you live, you don't file for it. You do file for child support in the nation where you live. In custody, have you filed for divorce or child support?

ANY question on law needs to include your general locale as laws vary by area. As Chuck noted, you don't "file for abandonment". What you want to file for is child support. You may use abandonment as grounds, but you don't file for it.

You file for support in the area where you legally reside. The child's citizenship or the father's probably don't apply in filing for support.. Though it may apply when trying to collect the support order.

If he has disappeared and you have no knowledge of where he is, how do you think you are going to collect support? This doesn't mean you shouldn't file, you should to establish that support is owed. But the likelihood of collecting any support if you do not know where he is, will be very small.

Gee.. thanks guys! I think I got confused with child abandonment and child support.
Anyway, I don't think I can file any child support here in my country since God knows how thousands of mothers file for this kind of case and got nothing at all!

Here in the Philippines you can get away with murder! I guess I have to take care of my child until she's old enough to go the US and claim her birthright.

Thank you so much for your replies! I do appreciate all of it. God bless you!

Like I said, filing and collecting are two different things. If you don't file and have a support award on record, then there is no "birthright".

Whether you collect or not is a different story.