When i get us citizenship after marriage of US citizen?

The applicant is a permanent resident ("green card" holder) with valid green card for a period of the past 5 years. If married to U.S. Citizen you may apply after 3 years with valid green card. One exception prevails - if an applicant has served in the United States armed forces during war, that individual may obtain US citizenship without first becoming a permanent resident if they were in the United States upon enlistment into the U.S. military.