Based　on　a　dual-polarization　dual-parallel　Mach-Zehnder　modulator　(DP-DPMZM),　an　all-optical　frequency　divider　is　proposed　and　experimentally　demonstrated.　Two　radio　frequency　(RF)　signals　are　modulated　on　an　optical　carrier　to　work　as　a　dual-beam　master　laser　(ML).　The　optical　signals　of　the　ML　are　injected　into　a　distributed　feedback　(DFB)　laser　to　initiate　the　period-two　(P2)　state　oscillation.　By　beating　the　output　of　the　slave　laser　(SL)　via　circulator　in　a　photodetector,　a　frequency　divider　with　tunable　factors　can　be　achieved.　The　innovation　of　the　scheme　lies　in　having　a　simple　structure　and　only　requires　optical　devices,　which　is　operated　in　wide　RF　frequency　range　without　any　electrical　amplifiers　before　the　photodetector　to　increase　the　conversion　gain.　Experiment　results　also　demonstrate　that　the　frequency　division　factors　can　be　adjusted.