In order to study the effect of individual growth on beak morphology of Dosidicus gigas, the samples of the jumbo flying squid were collected by the Chinese jigging fleet between 2009 and 2014 off the Peruvian Exclusive Economic Zone (79°22'-84°30'W, 10°00'-18°16'S). The beaks were extracted from 1208 samples and 12 morphometric parameters of beaks were measured. Meanwhile, the microstructure of beak was used to estimate the age of D. gigas. The differences of beak morphometry were analyzed which were influenced by body size, age and sexual maturity. The results showed that upper hood length (UHL), upper crest length (UCL), upper lateral wall length (ULWL), lower crest length (LCL), lower rostrum length (LRL) and lower lateral wall length (LLWL) could be used to represent the length features of beak. The ANOVA indicated that morphologic parameters of beak had significant differences between females and males, the average of the beak morphometric parameters of females was greater than that of males. The Least Significant Difference (LSD) analysis showed that the growth of beak between females and males varied according to mantle length, age and sex maturity. The growth had differences among the sections of beak of same sex individuals. However, if the mantle length is greater than 400mm, the age of female is greater than 300 days, the age of male is greater than 250 days or the sex maturity stage is greater than stage 3, then the growth of beak is slow. This study suggested that the morphometry of beak was influenced by body size, age and sex maturity.