Based on the1840 samples of Japanese Common Squid (Todarodes pacificus) collected during January to March in the Spring season in the La Ni?a year of 2018 in the East China Sea, the fisheries biological characteristics of T. pacificus was studied. The result indicated that the mantle length (ML) range was from 92 mm to 270 mm and 103 to 267 mm with a dominated concentration in180 mm to240 mm and 140 mm to 220 mm accounting for about 71.44 and 89.31percentages for females and males, the body weight (BW) range was from 21 g to 453 g and 21 g to 465g with a dominated concentration in120 g to270 g and 60 g to 180 g accounting for about 66.54 and 81.26 percentages for females and males, respectively. The ration of the somatic body weight (SBW) to BW ranged from 21.89 to 87.76 percentages with an average of 49.14 percentages. There was no significant difference between the BW and SBW growth in sex, and the relationships between the ML to BW and ML to SBW were both best described by the power functions by the result of Akaike’s information criterion (AIC). The ration of females to males was 1:1.255, and the samples were most composed of maturity individuals accounting for about 50.85 and 54.81 percentages for females and males. The feeding stage were mainly in 1 and 2 grade accounting for 64.24 percentages all of the specimens and the prey was mainly composed of squids, pelagic fishes, mollusc and crustacean and so on. It seemed that the fisheries biological feature of T. pacificus was affected by La Ni?a year with a decrease in the body size, a faster growth speed and advanced gonad maturity stages.