Studies on the reproductive biology of species Goniusrosaurus hainanensis was conducted first time from September 2017 to August 2019 basis on 147 of females and 179 males in the Diaoluoshan National Nature Reserve on Hainan Island. The breeding season of this species lasted from March to October but peaked in two months from July to August, respectively. The gravidity ratio of total females reached to 53% and the individual fecundity was 1.9 ± 0.5 eggs, of 80% of females had 2 eggs. In addition, the females had the ability to produce multiple clutches per year. Egg size, clutch size, egg lengths, and egg widths did not significantly correlated with the reproductive characteristics and snout-vent lengths of female individuals. Egg incubation temperatures were 22﹣26 ℃, incubation humidity was 80%﹣95%, incubation periods were 65﹣70 d (n = 4), and duration of the egg-breaking stage was lasted approximately 2 h (n = 4). The ratios of females to males and adults to larvae were 1︰1.2 and 8︰1, respectively. There was no sexual dimorphism with respect to body size.