Abstract: Objective :To investigate the expression of EphrinA1,Ephrin receptor EphA2 and E-cadherin in renal cellcarcinoma and to explore its relevance to the clinicopathologic features. Methods :The expression of Ephri-nA1,EphA2 and E-cadherin was detected by immunohistochemistry (IHC) in tissues from 68 cases of renalcell carcinoma and 24 normal kidney tissue samples.Flow cytometry (FCM) was used to quantitate the ex-pression of EphrinA1,EphA2 and E-cadherin. Results :Compared with normal kidney tissues,renal cell carci-noma tissues had higher expression of EphrinA1and EphA2 (P<0.01) and lower expression of E-cadherin (P<0.01).Compared with carcinoma tissues of lower grade and less advanced stage or with no lymph nodemetastasis,tissues of higher grade and advanced stage or with lymph node metastasis had higher expressionof EphrinA1 and EphA2 (P<0.01) and lower expression of E-cadherin (P<0.05).The expression of these threeproteins was not associated with tumor diameter,age or gender (P>0.05).The expression of EphrinA1 orEphA2 was independently and inversely correlated with E-cadherin expression (r=-0.483,P<0.01 for EphA2,r=-0.414,P<0.01 for EphrinA1).A positive correlation was found between EphA2 expression and EphrinA1 ex-pression (r=0.906,P<0.01). Conclusion :EphrinA1,EphA2 and E-cadherin may be involved in the occurrence,development and metastasis of renal cell carcinoma.Simultaneous detection of the three proteins might behelpful for evaluating the malignance and predicting the metastatic potential of renal cell carcinoma.