To understand the reproductive biological characteristics of the purpleback flying squid （Sthenoteuthis pteropus） in the Eastern Central Atlantic Ocean， this study analyzed reproductive traits including gonad maturity， size at sexual maturity， age at first maturity， and gonadosomatic index based on samples collected from the high seas of the eastern central Atlantic by Chinese squid jigging vessels from September to November 2022. The results showed that during the survey period， the female-to-male sex ratio of S. pteropus was 2.2∶1. The mantle length at first maturity was 258.3 mm for females and 206.3 mm for males. Immature individuals dominated in females， whereas mature individuals were predominant in males. The age range was 86-208 days. The estimated age at first maturity was 225.1 days for females and 166.1 days for males. It is inferred that hatching occurred from February to August in the survey area， with a peak period from June to August. The gonadosomatic index developed slowly in females at stages Ⅰ-Ⅱ， but increased rapidly at stages Ⅲ-Ⅳ and was significantly higher than that of males. The analysis indicates that the surveyed population belongs to a small-sized early-maturing equatorial group， which was in the pre-spawning phase of the reproductive season. This group matures and spawns in equatorial waters， and its spawning strategy is suggested to be that of an intermittent spawner.