A paper feeding system has a housing, a paper tray, a paper path positioned before a front end of the paper tray, a paper engaging mechanism installed above the paper tray, a paper separating mechanism, and a driving device. The paper engaging mechanism comprises an engaging arm and an engaging roller. The engaging arm comprises a first fixing shaft rotatably installed on the housing, and a second end installed with the engaging roller. When the engaging arm swings down to the paper tray, the engaging roller pushes at least a sheet of paper from the paper tray to the paper path. The paper separating mechanism comprises a separating roller and a friction pad installed respectively above and below the paper path. When two sheets of paper pass between a gap between the friction pad and the separating roller, the separating roller will move only the top sheet forward. The driving device is used to drive the engaging arm, the engaging roller, and the separating roller. When the driving device begins to run, the engaging arm will rotate down to the paper tray, and the engaging roller will rotate and move the sheet of paper from the paper tray into the paper path. Then the separating roller of the paper separating mechanism will successively move individual sheets along the paper path.