Abstract: To understand control timing of different dominant natural enemies against Aphis glycines, the species and population size of natural enemies of Aphis glycines in soybean fields were investigated in Harbin. Orius sp., Propylea japonica (Thunberg), Harmonia axyridis (Pallas), Chrysoperla nipponensis (Okamoto) and Aphidencertus sp. were dominant natural enemies in soybean field. At the initial occurrence of A. glycines, Orius sp. and P. japonica adults were dominant. During the population growth phase of A. glycines, Orius sp. and P. japonica adults, P. japonica and H. axyridis larva, and Aphidencertus sp. played a key role in decreasing aphid's growth rate. During the peak period of A. glycines, Orius sp. and H. axyridis adult, P. japonica and, C. nipponensis larva, and Aphidencertus sp. exerted an important role in checking aphid population. During the population decline period of A. glycines, Orius sp. nymph, P. japonica and H. axyridis adult, and Aphidencertus sp. reduced A. glycines population size for overwintering.