Objective To study the expression of cyclinD1 in congenital and acquired cholesteatoma and its significance. Methods 25 samples of congenital cholesteatoma, 35 of acquired cholesteatoma and 3 of normal auricle skin in the patients of chronic otitis media were included. The expression of cyclinD1 in these samples was detected with immunohistochemical method. Results CyclinD1 was positively expressed in cholesteatoma, but not in normal skin. As in the cholesteatoma, the positive rate of cyclinD1 in acquired ones was significantly higher than that in the congenital and the difference was statistically significant (P<0.01). Conclusion Acquired cholesteatoma has stronger proliferation ability than congenital cholesteatoma, which may be caused by inflammatory stimuli.