Objective:To examine the expression of Fas and Fas ligand(FasL) in cultured infantile hemangioma endothelial cells (IHECs).Methods: IHECs were isolated and cultured by explant combined with trypsin-digested techniques.Then the expression of Fas and FasL on cultured endothelial cells (ECs) were detected by flow cytometry (FCM) and fluorescent quantitative polymerase chain reaction (FQ-PCR) 2-ΔΔCT method,and the results in ECs were compared with those in Jurkat cells (positive control) and Human umbilical vein endothelial cells(HUVECs,negative control).Results: The positive rate of Fas in cultured IHECs was (90.97±2.36)% as detected by FCM,similar to that in the Jurkat cells (\[93.87±1.64\]%，P>0.05) and significantly higher than that in the HUVECs (P<0.01).Fas mRNA expression in the cultured IHECs was 1.260±0.721 as detected by FQ-PCR,and was 1.448±0.059 in Jurkat cells,with their ratio being 0.87 and with on significant difference found between the 2 group(P>0.05); the ratio of IHECs to HUVECs (0.354±0.170) was 3.56 and there was significant difference between the 2 groups (P<0.01).The expression of FasL mRNA in cultured IHECs,Jurkat cells and HUVECs was too low as detected by FCM and FQ-RCR to have any biological significance.Conclusion: Fas mRNA is highly expressed in cultured IHECs and FasL is rarely expressed in IHECs,which indicates that apoptosis of IHECs is associated with high expression of Fas in IHECs.