To compare the amount of periimplant bone resorption and the degree of aseptic looseningof the implant induced by various kinds of wear particles released from artificial joint. Method:Three special particles of UHMWPE, Ti-6Al-4V and Co -- Cr-- Mo were used respectively to inducethe change of periimplant bone structure and the loosening of a well-fixed implant made of titaniumalloy in rabbit femur or tibia. The bone structure was observed from X-ray film with computerizedimage analysis system(CIAS) and implant loosening was assayed by push-out test. All data werestatistically analysed. Results Ti-6Al-4V particle induced the less periimplant bone loss and the lesssevere implant loosening than UHMWPE particle or Co-Cr-Mo particle did. Conclusion: Variouskinds of wear particles with the same size and same amount can produce different degree of implantloosening.