Abstract: 【Objective】 The study aims to clarify the intraguild predation of Coccinella septempunctata on Harmonia axyridis with different extraguild prey species and densities, expecting to provide a theoretical basis for the comprehensive application of the two types of predatory ladybugs to control C.juglandicola and P.juglandis. 【Methods】 In the climatic chamber with a constant temperature of (25±1)℃, (60±10)% RH, and photoperiod of 14∶10(L∶D)h, the number of daily average predation of 1st instar larvae of C.septempunctata on eggs of H.axyridis and walnut aphids were evaluated. 【Results】 The results showed that the number of daily average predation of C.septempunctata on eggs of H.axyridis decreased significantly while on C.juglandicola and P.juglandis increased significantly with the increasing density of C.juglandicola and P.juglandis.With the extraguild prey P.juglandis, the intraguild predation of 1st instar larvae of C.septempunctata on eggs of H.axyridis decreased faster compared with the extraguild prey of C.juglandicola as the increase of prey density. 【Conclusion】 With the increase of extraguild prey density, the intragruild predation of C.septempunctata on H.axyridis can be effectively reduced, and the effects of different prey species were different.