Objective To study the effects of Saccharomyces albicans（S.albicans） on the cell cycle distribution and proliferation of human umbilical vein endothelial cell ECV304 cells in vitro. Methods The line of ECV304 cultured in vitro were divided into four groups which were treated by S.albicans supernatant, S.albicans inactivated bacilli, supernatant and inactivated bacilli mixture, normal culture medium. The proliferous effect of ECV304 induced by supernatant, inactivated bacilli, supernatant and inactivated bacilli mixture using the methods of MTT, cell count, microscope and flow cytometry were conducted. Results In the condition of different times and different culture concentrations, ECV304 cells incubated with 4-fold diluted S.albicans supernatant for 48 h increased the proliferation rate. The S and G2/M population of ECV304 cells increased after incubated with S.albicans supernatant for 40 h, which showed significant increasing cell proliferation index（PI）（P0.05）. Conclusion S.albicans could induce ECV304 cell proliferation which depends on the release of metabolic products of S.albicans.
