Abstract: In order to confirm the effect of intercropping of soybean and garlic or Chinese onion on soybean aphid, the author has made a survey in the fields with soybean monocropping, soybean garlic intercropping and soybean Chinese onion intercropping by chessboard-sampling method. The survey date was from full incidence beginning period to harvest time of garlic or Chinese onion later 2 weeks. The survey was made every seven days. The results showed that the numbers of soybean aphid in fields by intercropping of soybean and garlic or Chinese onion were lower than soybean monocropping’s. It is possible to control soybean aphid with different tillage methods of crops.