Objective The purpose of this study was to evaluate the changes of masticatory performance of the cases wearing dentures and relative factors. Methods The changes of masticatory performance of the cases wearing dentures were studied before and after wearing场using the light absorption method and peanuts as test food. Restdts The mastication performance of the expenmental groups was predominantly lower than that of the control groups. The masticatory performance was gradually improved with wearing denture period increasing. Factors relating to the masticatory performance were age, number of occlusal units lost and the kind of denture, and the number of chewing etc. Conclusion The mastication performance of the experimental groups was dominantly lower than that of the control groups, but gradually improved with wearing denture period increasing. Varied factors af fect the masticatory performance of experimental groups.