Objective:To investigate the effect of nifedipine(calciumchannel blocker) on the expression of collagen in gingival fibroblasts invitro. Methods:Primarily gingival fibroblasts were cultured and incubated with various concentrations of nifedipine(108μg/L, 360μg/L and 1200μg/L)for 5 days. Gingival fibroblasts were primarily cultured derived from nifedipine responders and non-responders in the presence of 360μg/L nifedipine. Enzyme-linked immunosorbent assay was used to evaluate the amount of type I collagen. Cell proliferation was measured by cell counting with evaluating MTT value. Results:The expressions of collagen and cell proliferation were significantly different among the high concentration groups and the others on the fifth day, especially higher in 360μg/L and 1200μg/L groups and also different among nifedipine responders and non-responders. Conclusion:The expression of collagen and cell proliferation may be concerned with the biological mechanism for gingival overgrowth.