Abstract: Dmrt is a gene family that is homologous to Doublesex in Drosophila melanogaste and Mab-3 in Caenorhabditis elegans. Dmrt genes encode a large family of transcription factors including a characteristic conservative zinc finger DNA-binding domain (i.e., DM domain). This ancient gene family has been identified in animal groups ranging from invertebrates to vertebrates. Their biological functions include sex determination and differentiation, construction of tissues and organs, and maintenance related functions. This paper reviews the recent progress of Dmrt genes in hydrobionts with theirs functions in line of evolution from invertebrates to vertebrates. We analyzed the course of sex determining gene for Dmrt genes.We further presented prospects of their future research in hydrobionts.