According to 854 samples of Ommastrephes bartramii, collected by squid jigging vessel in the east central waters of North Pacific Ocean during April to July in 2010, the mantle length (ML) composition, sex ratio, sexual maturity and other biological properties in the two areas (170°E-180°E and 170°W-180°W) are analyzed and compared. The results showed that the dominant ML of female was 25-29 cm and 35-43 cm, the average ML was 32.9 cm in the waters of 170°W-180°W, and the dominant ML for male squid was 23-27 cm and the average ML was 24.5 cm. While in the waters of 170°E-180°E, the dominant ML for female squid was 35-43 cm and the average ML was 36.9 cm, and only one male squid was sampled. The relationship between weight and ML showed that the females grow faster than males, especially in waters of west longitude. The sexual composition in the catch does not meet 1∶1. In the areas of 170°W-180°W , the female maturity for Ⅰ and Ⅱ stages accounts for 97.9% of the total, and the corresponding dominant ML were 23-27 cm and 35-43 cm respectively, the dominant ML for Ⅲ maturity stage is 45-49 cm. For the male sexual maturity, stages Ⅰ and Ⅱ are most and the corresponding dominant ML were 23-27 cm and 25-27 cm respectively. In the areas of 170 ° E-180 ° E, the female maturity for stages Ⅰ and Ⅱ is the main part and the corresponding ML was 29-35 cm and 35-43 cm respectively. The female MLs of first maturity were 47.3 cm and 50.7 cm in the waters of 170°W-180°W and 170°E-180°E respectively. It is concluded that all samples belonged to the fall spawning group, the largesize group is the main part and there are a few smallsize groups in the waters of 170°E-180°E, and smallsize group and largesize group are of the same proportion in the waters of 170°W-180°W.