A paper stopper mechanism for paper-feeding apparatus, which has simplified structure and commonly uses one motor to stop papers. The paper stopper mechanism includes a rotary shaft driven by a drive shaft via a gear assembly, a stopper plate disposed on the rotary shaft, which is movable between a first position and a second position along with the rotation of the rotary shaft, and a resilient member positioned between the rotary shaft and a transmission gear of the gear assembly. There is frictional force between the rotary shaft and the transmission gear, whereby the transmission gear can drive the rotary shaft to rotate. When the stopper plate and the rotary shaft stop at the second position, the transmission gear can still transmit power to a pickup roller to feed a paper into the paper-feeding apparatus without any error.