ObjectiveTo evaluate the inhibiting effects of mitomycin C（MMC） on fibroblasts of human pterygium （HPF） in vitro．MethodsThe fibroblasts derived from the 5 th to 8 th generation of the cultured tissues in human pterygium．These fibroblasts were exposed to culture plates with MMC at 6 gradient concentrations，adjusting the concentration value of the culture medium to 105，104，103，102，10 and 1 μg/L．The cells had been treated with PBS in the control group．After 48 h of incubation，the absorbency had been determined individually by MTT［3-（4，5-dimethylthiazol-2-yl）-2，5-diphenyl-tetrazolium bromide］ method.The inhibitory rates were calculated accordingly．All the data were analyzed with student t test and linear regression．ResultsThe extensive breakage of fibroblasts was observed．There was a statistical difference between the tested group and control group in absorbency (P＜0.05)，especially at the concentrations of more than 100 μg/L (P＜0.01)．The degree of growth inhibition increased with exposure of cells to MMC over 48 h．It showed that there is a positive correlation between the doses of MMC and the antiproliferative effects on HPF．ConclusionMMC significantly inhibites the proliferation of HPF in a dose-dependent manner．