Shen is a small crustacean belonging to the arthropods. It is distributed within the low tide areas of the intertidal zone. It has a delicious taste and high nutritional value. At present, there are very few studies about . Existing researches have focused on the classification, morphology, nutrition, and genetic diversity. There has been no research on the relationship between the morphological traits and weight characteristics. To study the relationship between the morphological characteristics and weight traits of , fourteen biological indicators were measured, including carapace height (), carapace spine length (₁), carapace width (), first abdominal segment length (), pincers length (W_W), and dry weight (). These were studied by means of correlation analysis, path analysis, and regression analysis. The results showed that the female crabs had significantly higher values than the males for the 14 quantitative indicators (0.01). The coefficient of variation for the weight indicators was greater than that for the morphological traits, and the morphological and weight indicators were significantly correlated (0.01). For male individuals, the direct effects and direct determination coefficients of the body length, carapace spine length, and spine width for the wet and dry weights were larger. For female individuals, the direct effects and direct determination coefficients of the body length and carapace width for the wet and dry weights were larger. The regression equations for the morphological traits of the male and female individuals for the wet weight were W₂, respectively. The regression equations for the morphological traits of the male and female individuals for the dry weight were =-2.65 + 0.098 respectively. The indicators for morphological and weight traits of the male and female individuals were significantly different (0.01). The coefficient of variation for the weight index was greater than that for the morphological index. This shows that the selection of weight indicators has great potential, and it is feasible to carry out selective breeding of with weight as the target trait. Stepwise regression analysis showed that the main indicator affecting male wet weight was body length (), while the main indicators affecting female wet weight were body length () and spine width () have a greater decisive effect on dry weight of males, while body length () had a greater role in the dry weight of females. This study provides references for the evaluation of breeding.