Objective To observe the influences of estradiol (E2), basic fibroblast growth factor (bFGF), and tamoxifen (TAM) on the proliferation of hemangioma vascular endothelial cell (HVEC). Methods Two strawberry hemangioma from 2 infants (case 1 and case 2) were prepared for HVEC culture. The HVEC on passage 3 were cultured in estrogenfree improved minimum essential medium (IMEM) and subjected to various treatments with 100 pg/ml 17-β-E2, 10 ng/ml bFGF, and 1×10-6 mol/L 4-OH-tamoxifen(4-OH-TAM). The experiment was divided into 5 groups: group 1(IMEM, control group), group 2(17-β-E2), group 3(bFGF), group 4(17-β-E2／bGFG) and group 5(17-β-E2／bGFG／4-OH-TAM). The cell count(CC) and DNA proliferation index (PI) were determined. Results Two cases of HVEC were successfully cultured in vitro. The HVEC showed cobblestoneslike under microscopy and factor Ⅷrelated antigen(also named as von Willebrand factor，vWF) was positive by immunochemical staining. At 9 days in case 1: CC and PI remained unchanged in the control group; CC and PI were slightly increased in group 2, being 1.4 and 1.6 times as much as those in the control group respectively (P＜0.05); CC and PI significantly increased in group 3, being2.6 and 2.3 times as much as those in the control group respectively (P＜0.01); CC and PI increased remarkably in group 4, being 3.7 and 2.9 times as much as those in thecontrol group respectively (P＜0.01); CC and PI were down to the levels of controls in group 5(P＞0.05). The results in case 2 were similar to those in case 1. Conclusion In vitro, the promoting effect of bFGF on HVEC proliferation is much ber than that of estrogen. Estrogen and bFGF enhance this proliferation in a synergistic manner, which can be inhibited by tamoxifen.