Using the hight-analysis method founded by American geographer strahler A. N. ,the charactors of erosive geomorphy of Dacha gully have been quantitavely computed and analysed. This conclusion could provide a scientific base for the optimum arrangement and comprehesive harness in the area. For the present，the general harness degree reachs 94.40，soil erosion has been basically controlled，and 4 OOOm' of the runoff can be harvested，it improved the developement of water saving agriculture.