In order to explore the effects of mixture of microbial culture and chemical fertilizer on promoting assimilation of nutrients and controlling nitrogen and phosphorus leaching， a certain volume of microbial culture and different amounts of fertilizer were mixed and added into potted rape. After harvesting the rape， biomass and nitrogen， phosphorus， potassium contents of rape were measured， and the physical and chemical properties of soil in different layers were analyzed. The results showed that the rape biomass of T5( 50 mL microbial culture， 1.2 g urea and 0.72 g NaH2PO4·2H2O was mixed and added into rapepot containing 4.5 kg soil) was the highest among all treatments， and the rape had high assimilation on nitrogen，phosphorus and potassium. With the increase of chemical fertilizer， the available phosphorus of top soil increased slowly，while the available phosphorus of subsoil had no significant difference with that of the control. When chemical fertilizer level was lower than that of T5， the ammonium nitrogen of topsoil was higher than that of the control and the nitrate nitrogen showed reverse change， and the ammonium nitrogen and the nitrate nitrogen of subsoil had no significant difference with the control，which showed low leaching of nitrogen. When the chemical fertilizer was higher than that of T5， the ammonium nitrogen and the nitrate nitrogen of topsoil were significantly higher than that of the control， and the nitrate nitrogen of subsoil increased insignificantly. However ammonium nitrogen of subsoil increased significantly， which increased the risk of nitrogen leaching. Microbial culture activated potassium in the soil， which promoted the absorption of rape on potassium. The research indicated that the mixture of microbial culture and an appropriate amount of chemical fertilizer was helpful to reduce the amount of chemical fertilizer but did not reduce the yield， have a certain inhibitory on nitrogen and phosphorus leaching， and promote the absorption of rape on potassium from soil.