Abstract: The nutrient composition, yield, water-holding capacity, texture and microstructure of Procambraus clarkii meat from April to June 2020 and three sizes (S: 10~20 g, M: 20~30 g, L: 30~40 g) of crayfish were analyzed and compared. The results showed that the moisture content of crayfish meat tended to decrease with the month of harvesting from April to June, the ash content of crayfish meat was highest in the three sizes of crayfish in May, the 6-S protein content was highest in the S group in June, and the 4-L crude fat content was lowest in the L group in April. The crayfish meat yield decreased with size and month. The pH of crayfish meat was mainly neutral (7.09~7.22). The water-holding capacity of L decreased with increasing sampling month, and the crayfish of S and M showed a trend of decreasing and then increasing. The surface hardness of crayfish flesh gradually decreased and internal hardness increased significantly (P<0.05) with increasing sample size, and the elasticity of crayfish flesh first increased significantly (P<0.05) and then did not change significantly in the S group, while the elasticity of M and L group did not change much. The muscle fiber gap size corresponded to the water-holding capacity, and the gap between liver vesicles was the smallest in the L group in June. The correlation analysis showed that the lower the flesh yield of crayfish, the smaller the gap between muscle fibers, and the more Q-textured and nutritious the crayfish meat. This study provides data to support the commercialization of crayfish in different sampling months and sizes.