Objective To evaluate the effect of copper-ion on the prol iferation and differentiation of human umbil ical vein endothel ial cell (HUVEC). Methods HUVEC were cultured and passaged in vitro. HUVEC were inoculated into 96-well plate with density of 5 × 103/well. All the cells were divided into 3 groups randomly according to different culture mediums: group A (5 μmol/L CuSO4), group B (25 μmol/L CuSO4), group C (control group). Every group had 4 wells, and the basic culture medium was MCDB131. The cell growth curves of 3 groups were drawn by using MTT. HUVEC were inoculated into 6-well plate with density of 2 × 105/well. Grouping of the cells was the same as the above. The gene expressions of endothel ial nitric oxide synthase (eNOS) and tyrosine kinase with immunoglobul in-l ike and EGF-l ike domain 1 (Tie-1) were detected by real-time RT-PCR. Results The growth curves revealed that the exponential growth time was the first 3 days, plateau growth time begun on the 4th day. The prol iferation of group A was ber than that of groups B and C from the 3rd day, within 2 days, the prol iferation of group B was ber than that of group C; however, it decreased and was weaker than group C from the 4th day, all showing statistically significant difference (P lt; 0.05). The results of real-time RT-PCR revealed that the expressions of eNOS in groups A, B and C were 7.294 ± 1.488, 0.149 ± 0.044 and 1.000 ± 0.253; and the expressions of Tie-1 in groups A, B and C were 1.481 ± 0.137, 1.131 ± 0.191 and 1.000 ± 0.177. Group A compared with groups B and C, both of 2 genes were up-regulated (P lt; 0.05). Group B compared with group C, eNOS was down-regulated (P lt; 0.05) and the difference of Tie-1 expression was not statistically significant (P gt; 0.05). Conclusion 5 μmol/L copper-ion can promote the prol iferation and differentiation of HUVEC effectively.