Objective This study aims to research the effect of different concentration of ulinastatin on the proliferation, apoptosis, migration, adhesion of the human umbilical vein endothelial cells. Methods First, cultivate the primary human umbilical vein endothelial cell (HUVEC) until the fourth generation. Divide the cells into the control group (U) and concentration respectively are 625, 2 500, 5 000, 10 000 U/ml (group A, B, C, D). And then the CellTrace experiment, TdT-mediated dUTP nick end labeling (TUNEL) experiment, scratch assay, cell adhesion assay were respectively applied to detecte the proliferation, apoptosis, migration, adhesion of HUVEC. Results Wound healing assay: The 6 hours' migration rates of group U, A, B, C, D are 4.08%, 2.61%, 5.24%, 3.99%, 2.27%, the 24 hours' migration rates of group U, A, B, C, D are 12.53%, 13.04%, 20.65%, 21.37%, 30.10%, the 48 hours' migration rates of group U, A, B, C, D are 20.18%, 25.00%, 37.92%, 49.22%, 49.01%. Cell proliferation assay: The rates of prolification of group U, A, B, C, D are 60.1%, 70.3%, 77.2%, 82.1%, 88.5%. Cell apoptosis assay: The rates of apoptosis of group U, A, B, C, D are 3.1%, 2.5%, 2.1%, 2.3%, 35.3%. Cell adhesion assay: The percentages of cell attachment of group U, A, B, C, D on BSA group are 38.0%, 39.0%, 41.0%, 43.0%, 43.0%, the percentages of cell attachment of group U, A, B, C, D on matrigel group are 50.0%, 51.0%, 54.0%, 61.0%, 66.0%, the percentages of cell attachment of group U, A, B, C, D on FN group are 60.0%, 61.0%, 64.0%, 73.0%, 81.0%. Conclusion In this study, ulinastatin can accelerate the proliferation, migration and adhesion of the HUVEC cultured in vitro; but high concentraction of ulinastatin can lead to cell apoptosis. Key words: Ulinastatin; Human umbilical vein endothelial cells; Proliferation; Apoptosis; Migration; Adhesion