大体上，18岁以上、绿卡和时间要求。
无刑事记录，品性良好（非酒鬼、职业妓女妓男、职业赌徒、贩毒卖毒、重婚、不赡养孩子、欺骗美国政府）。
不需要报税记录。
如果隐瞒不良记录归化成公民，事发之后将直接被剥夺公民身份并驱逐出境。
Generally, an applicant must show that he or she has been a person of good moral character for the statutory period (typically five years or three years if married to a U.S. citizen or one year for Armed Forces expedite) prior to filing for naturalization. The Service is not limited to the statutory period in determining whether an applicant has established good moral character. An applicant is permanently barred from naturalization if he or she has ever been convicted of murder. An applicant is also permanently barred from naturalization if he or she has been convicted of an aggravated felony as defined in section 101(a)(43) of the Act on or after November 29, 1990. A person also cannot be found to be a person of good moral character if during the last five years he or she:
has committed and been convicted of one or more crimes involving moral turpitude
has committed and been convicted of 2 or more offenses for which the total sentence imposed was 5 years or more
has committed and been convicted of any controlled substance law, except for a single offense of simple possession of 30 grams or less of marijuana
has been confined to a penal institution during the statutory period, as a result of a conviction, for an aggregate period of 180 days or more
has committed and been convicted of two or more gambling offenses
is or has earned his or her principal income from illegal gambling
is or has been involved in prostitution or commercialized vice
is or has been involved in smuggling illegal aliens into the United States
is or has been a habitual drunkard
is practicing or has practiced polygamy
has willfully failed or refused to support dependents
has given false testimony, under oath, in order to receive a benefit under the Immigration and Nationality Act.
参考资料：http://en.allexperts.com/q/Immigration-Issues-344/Naturalization-past-felony.htm