Abstract: Morphological study is the basis of marine biology and is of great significance for understanding the composition of fishery stock. Using the morphological parameters of 940 Uroteuthis chinensis samples collected in Shantou-Taiwan Strait Bank fishing ground from July 2018 to June 2019, we studied the group composition and the relationship between mantle length (ML) and weight. Principal component analysis (PCA) was used to analyze the ratios among morphological parameters to determine the main components of the morphological differences. Besides, 4 functions, linear, exponential, power function and Logistic, were used to fit the curves of relationship between mantle length and other morphological parameters which contain four wrist length (AL₁,AL₂,AL₃,AL₄), touch wrist length (TL), fin length (FL) and fin width (FW), and the best-fitting function was selected and applied. The results show that the maximum, minimum and average mantle length of Uroteuthis chinensis are 50.00 mm, 300.00 mm and 111.44 mm, respectively. The mantle weight (MW) ranges from 7.43g and 301.00g with average of 53.95 g. And the growth coefficient b of females and males is 2.2696 and 2.067 5, respectively. Therefore, females grow faster than males while individual sizes trend toward miniaturization. PCA result showed that the difference of morphological parameter ratios can be optimized into two principal components. The first principal component mainly explains the differences of all of the wrist length and fin width between females and males. The second principal component mainly demonstrates the difference of fin length. And the second principal component has a more obvious manifestation in the factor visualization map. The best-fitting function of the relationship between mantle length and morphological parameters is of linear function. There are significant differences between females and males in the relationship between mantle length and morphological parameters. Thus, the results can provide more basic data for the fishery biology of Uroteuthis chinensis and more understanding about the composition and changes of the resource population for the sustainable use and scientific management of the stocks.