Sex steroid receptors belong to the members of the nuclear receptor superfamily that are ligand-dependent transcription factors which play key role in the reproductive endocrine both in vertebrates and invertebrates. The structure and signaling transduction of nuclear sex steroid receptor as well as the mechanism of action about receptor and binging ligand in amphioxus are introduced in the paper. At the same time, this review will provide new information for the evolution of nuclear sex steroid receptor.