Chinese sturgeon (Acipenser sinensis), a critically endangered Acipenseridae family member, is one of the largest anadromous, native fish in China. Numerous research programmes and protection agencies have focused on breeding and preserving this endangered species. However, available information is limited on the different stages of sex development, especially on the reproductive regulation of the hypothalamus-pituitary-gonad (HPG) axis of A. sinensis. To unravel the mechanism of gene interactions during sex differentiation and gonad development of A. sinensis, we performed transcriptome sequencing using HPG samples from male and female A. sinensis in two developmental stages. In this study, 271.19 Gb high-quality transcriptome data were obtained from 45 samples belonging to 15 individuals (six in stage I, six males and three females in stage II). These transcriptomic data will help us understand the reproductive regulation of the HPG axis in the development stages of A. sinensis and provide important reference data for genomic and genetic studies in A. sinensis and related species.