Abstract: In order to research the predation of Pardosa pseudoannulata and Pirata procurva on Plutella xylostella larvae, the predation amount of P. xylostella larvae by the two spiders under different temperatures and the predation amount of P. xylostella larvae by P. pseudoannulata under different volumes were analyzed. Based on three factors in five levels, the quadratic general regression rotation combination design was used to study the combined control effect of the two spiders on P. xylostella larvae and the control effect of P. pseudoannulata on the larvae of P. xylostella and Spodoptera litura. The results showed that the predation amount of the two spiders on P. xylostella larvae increased first and then decreased with the increase of temperature, and the functional predation response of P. pseudoannulata and P. procurva on the fourth instar larvae of P. xylostella fitted with the Holling-Ⅱ model, and the Holling-Ⅲ model could perfect the predation effect. Different volumes had great effect on the feeding of P. pseudoannulata. Instantaneous attack ability (a''), the time preying one diamondback moth (T_h) and predation function (a''/T_h) in a small volume were higher than that in a larger volume. The predation of the two spiders on P. xylostella was positively correlated with their densities. The overall effect of the factors was the density of P. xylostella＞the density of P. procurva＞the density of P. pseudoannulata. The densities of P. xylostella and S. litura larvae could affect the feeding amount of P. pseudoannulata. But there was no predation preference for P. pseudoannulata on the larve of P. xylostella and S. litura. The results will provide a reference for the evaluation of control effect of P. xylostella by P. pseudoannulata and P. procurvus in the field.