If you are a U.S. citizen and the father or stepparent of the child or son or daughter, you must file the following with the U.S. Citizenship and Immigration Services:
Form I-130, Petition for Alien Relative
A copy of your birth certificate or U.S. passport
If you were not born in the U.S., a copy of either:
your Certificate of Naturalization or Citizenship or
your U.S. passport
A copy of the child’s birth certificate showing the child’s name and the names of both parents
A copy of civil marriage certificate showing the names of both parents, or proof that a parent/child relationship exists or existed (if you are petitioning for a stepchild, your marriage to the child’s parent must take place before the stepchild’s 18th birthday)
A copy of any divorce decrees, death certificates, or annulment decrees that establish the termination of any previous marriages entered into by you or your spouse
Fathers petitioning for a child born out of wedlock must provide evidence that a parent/child relationship exists or existed. For example, the child’s birth certificate displaying the father’s name, evidence showing that the father and child at some point lived together, or that the father held out the child as his own, or that he has made financial contributions in support of the child, or that in general his behavior evidenced genuine concern for and interest in the child. A blood test proving paternity may also be necessary.
If anyone’s name has been legally changed (if it differs from the name on his or her birth certificate), evidence of the name change must be submitted.
Hope this will help you!
Good Luck!