The development of sex-specific markers is important for the aquaculture industry, especially those fish that do not have obvious sex dimorphism. Golden pompano (Trachinotus blochii) is the famous famed species, it is currently one of the main species of southern China. In our study, with the whole genome resequencing data of fish from four locations in three different provinces (ZhangZhou, ZhanJiang, QiaoTou and NanShan), a total of 2,183,486 high quality clean reads were obtained for subsequent information analysis. Association analysis of SNP markers with sex was carried out with the simple linear regression model (Q) of genome-wide association study (GWAS), a high-scored site loci in LG20 exhibited significant association with sex was found.