Based on 1 214 greater lizardfish, Saurida tumbil, collected from the Beibu Gulf in 2020, the reproductive characteristics and its adaptive changes of the population were investigated by assessing the biological characteristics and ovary histology.The results showed that the overall sex ratio of female to male was 1.82∶1, the mature gonads of the female population were distributed in all four seasons, and the gonad somatic index (GSI) remained higher level from March to August, which was the main spawning season with the peak spawning occurring in March and July. Oocytes with different egg diameters were found in the mature ovaries, and obviously multi-modal type was showed in the distribution of egg diameters. The range of absolute fecundity was large (2 774–158 986), and there were oocytes at different developmental stages in the mature ovaries. Based on the results of GSI, spawning season, oocyte diameter distribution and histological sections, it is concluded that S. tumbil belongs to the non-synchronized multiple batch spawner. The relative fecundity (267 eggs/g) was maintained at a higher level, which was conducive to establishing a stable population rapidly under the high intensity fishing pressure. The estimated body length at the first sexual maturity (L₅₀) for females (19.0 cm) was the same as the body length of the important turning point of the sex ratio. In this study, it was found that the reproductive characteristics of S. tumbil in the Beibu Gulf had difference compared with the previous population. The results further enriched the reproductive biological data available for S. tumbil and provided a scientific basis for the protection and sustainable utilization of S. tumbil resources in the Beibu Gulf.