The aim of this study was to obtain the most recent data and investigate the biological characteristics under a changing environment for jumbo flying squid, collected by a Chinese squid jigging vessel from February to April 2018 in the eastern equatorial Pacific Ocean (110°W-114°W, 2°40'S-2°N). The distribution of mantle length (ML), body weight (BW), maturity stages, and stomach stages from February to April was studied using the frequency distribution method. The relationship between ML to BW and the first mature ML was obtained by best power exponent fit. The differences in the growth of female and male squids among different months were discussed based on the remote sensing temperature that was dependent on sampling location. Ranges of ML and BW of female squid were 20-46.7 cm and 240-3420 g, respectively, and averages were (30.6±4.47) cm and (939.07±460.02) g, respectively, whereas for males, ranges of ML and BW were 22.2-42.5 cm and 310-2270 g, and the averages were (31.3±3.93) cm and (925.57±358.6) g, respectively. The dominate ML of males in February, March, and April was 26-28 cm, 30-32 cm, and 28-30 cm, whereas females were 24-26 cm, 28-30 cm, and 26-28 cm, respectively. The dominate BW of males and females in February, March, and April was 400-600 g, 600-800 g, and 600-800 g, respectively. The equation of the relationship between ML and BW was fitted with the power exponent. The effect of sex on the exponent "" of the BW-ML relationship was significant in March, thus there was a significant difference in body growth between female and male individuals as revealed the analysis of covariance (<0.01). There were also significant differences in body growth among the three months for the same sex (<0.05). From February to April, the stomach stages of males and females were mainly 1 to 2 with the ratio of higher stomach stages decreasing with each month. The sexual ratio of females to males was 2.04:1. The maturity stages of males were mainly Ⅱ with the ratio of maturity stage increasing with each month. The ML at first maturity of males was 32.72 cm. The maturity stages of females were mainly I with the ratio of the immature stage accounting for greater than 97%. A linear relation was found for ML and BW and maturity stages for both male and female squid. From February to March was a period of rapid growth and development, especially for males. However, in April, the dominant group no longer grew. Thus, the maturity stages of males develop earlier than the maturity stages of females, and the mature males leave the equatorial waters and begin to migrate.