The molecular markers of Nile tilapia(N2 strain) have been accurately determined in the past study, and the progeny of the breeding of the specially selected species of fish are analyzed, and it is hoped that the future can be carried out without hormones. This year's random sampling of 200 tilapia's progeny and genotype analysis, 200 tilapia of a total of 90 YY genotype (45.2%); 109 tail XY genotype (54.8%), of which 1 can not read genotype. After statistical analysis, there is no significant difference between the test results and the expected values.