Yan Feng, 39, who lives in a suburb of the city, handed himself in to police on Friday, two days after the fire.
He is said to be a permanent US resident with no criminal record.
No-one was injured by the fire, but Chinese officials said the building was “severely damaged” and condemned it as a “vicious, destructive act of arson”.
Consular officials said an unidentified person had parked a van in front of the building then poured two cans of petrol on the main gate and set it ablaze.
FBI Special Agent in Charge David Johnson refused to discuss a motive for the crime, but said the agency was not investigating the case as an act of terrorism.
Mr Feng faces charges of property damages and arson.
“We’re looking at it purely as a criminal matter,” Mr Johnson said.