Abstract: To investigate the morphological differences between male and female E.oxycephala, and improve the breeding efficiency, principal component analysis, R-cluster analysis, stepwise discriminant analysis and T-test were used to analyze 17 direct-measured characteristics and 14 standardized characteristics of 60 wild individuals. The T-test showed that there was a significant difference in size between male and female E.oxycephala individuals, however there was no significant difference in plumpness between male and female individuals. The result of principal component analysis showed that the contribution percentage of the three extracted principal components were 66.989%, 7.803% and 4.901%, respectively, and the cumulative contribution rates reached 79.693%. Standardized characteristics with significant differences of E.oxycephala between male and female populations were selected by R-cluster analysis and stepwise discriminant analysis to establish the sex discriminant equation. The equation was as follows,male:F₁=-63.908X₁+626.425X₂+2 298.275X₃+173.546X₄ -55.640X₅-239.618,female:F₂=68.365X₁+510.204X₂+1 936.135X₃+150.444X₄ +48.164X₅-204.308. The comprehensive discrimination accuracy of male and female individuals was 98.3%. To verify the accuracy of sex discriminant equation, the morphological character data of extra 23 wild E.oxycephala were substituted into the sex discriminant equation, and the comprehensive discriminant accuracy was 82.6%.