In this research, we used the Gunne's spectrophotometry method to measure the masticatory efficiency in 30 skeletal Class III patients and in 55 normal people. After groups comparing and step wise-regression analysis, we found that masticatory efficiency in Class III malocclusion group was much lower than that in normal occlusion group, and the masticatory efficiency in Class III malocclusion was about 60% of that in normal peoples. Masticatory efficiency in male was higher than that in female.