·AIM:To investigate the expression of connexin 43 and epithelial cadherin (E-cadherin) in choroidal melanoma,to explore the clinical and pathological implications of expression of these proteins,and to determine their relations with malignant features.·METHODS:The expression of connexin 43 and E-cadherin in choroidal melanoma were detected by immunohist-ochemistry and correlated with clinicopathological features.·RESULTS:Positive rates of connexin 43 in choroidal melanomas and benign pigmented nevus tissues were 75% and 40% respectively with significant differences between the two groups (χ2=5.607,P =0.009).Positive rates of E-cadherin in choroidal melanomas and benign pigmented nevus tissues were 40￡$ and 75% respectively with significant differences between the two groups (χ2=5.214,P=0.010).Significant overexpression of connexin 43 and reduction of E-cadherin expression was associated with the invasion to the sclera,and there were respectively significant differences between without and with scleral invasion groups (χ2=2.880,P=0.040;χ2=2.778,P =0.046).Overexpression of connexin 43 were correlated with tumor cell types and the expression of connexin 43 and E-cadherin may be correlated with each other.·CONCLUSION:The increased expression of connexin 43 and the decreased expression of E-cadherin may be involved in the process of invasion of choroidal melanoma.The overepression of connexin 43 and reduction of E-cadherin may contribute to the development of choroidal melanoma.· To investigate the expression of connexin 43 and epithelial cadherin (in-choroidal melanoma, to explore the clinical and pathological implications of expression of these proteins, and to determine their relations with malignant features. METHODS: The expression of connexin 43 and E-cadherin in choroidal melanoma were detected by immunohist-ochemistry and correlated with clinicopathological features. RESULTS: Positive rates of connexin 43 in choroidal melanomas and benign pigmented nevus tissues were 75% and 40% respectively with significant differences between the two (χ2 = 5.607, P = 0.009) .Positive rates of E-cadherin in choroidal melanomas and benign pigmented nevus tissues were 40 £ and 75% respectively with significant differences between the two groups (χ2 = 5.214, P = 0.010). Significant overexpression of connexin 43 and reduction of E-cadherin expression was associated with the invasion to the sclera, and there were respectively significant differences between w ithout and with scleral invasion groups (χ2 = 2.880, P = 0.040; χ2 = 2.778, P = 0.046) .Overexpression of connexin 43 were correlated with tumor cell types and the expression of connexin 43 and E-cadherin may be correlated with each other . CONCLUSION: The increased expression of connexin 43 and the decreased expression of E-cadherin may be involved in the process of invasion of choroidal melanoma. Overepression of connexin 43 and reduction of E-cadherin may contribute to the development of choroidal melanoma. ·