The Chinese mitten crab （Eriocheir sinensis） is an important economic crab in China. It occupies an important position in the fishery economy, with an annual output value of more than 100 billion yuan. Although there are five E. sinensis varieties approved by China National Committee for Original and Improved Aquatic Species, they cannot fully meet the diversified needs of E. sinensis breeding industry. The breeding of super-sized E. sinensis broodstock has been a revolution in the crab industry since 2019. The use of offspring of super-sized broodstock for adult crab culture has indeed effectively improved the crab cultivation specifications. Super-sized broodstocks can produce a large number of eggs, and the offspring of super-sized broodstocks have obvious growth advantages at the juvenile crab stage and the adult crab culturing stage, and the price of megalopa bred by super-sized broodstocks is also relatively high. Therefore, nursery workers tend to use super-sized crabs as broodstocks for breeding work. However, in the artificial breeding process, the selection of broodstock weight of E. sinensis varies greatly. Now, it is popular to use super-sized broodstock to breed offspring, but the reproductive performance and breeding effect of super-sized broodstock are not clear. In this study, the broodstock of super-sized strains （Size Ⅰ： dam weight ≥300 g, sire weight ≥400 g） were used as the experimental object, and the broodstock with smaller size （Size Ⅱ： dam weight ≥150 g, sire weight ≥ 250 g） were used as the control group. The effects of broodstock sizes on reproductive performance and egg quality were compared, and the ecological breeding effects of these two strains were further discussed. The results showed that： （1） In terms of reproductive performance, the survival rate, fecundity and reproductive effort of Size Ⅰ broodstock were significantly lower than those of Size Ⅱ, and the egg production was significantly higher than that of Size Ⅱ； There were no significant differences in egg diameter, egg weight, moisture, crude protein, total lipid and ash contents. （2） In terms of breeding effect, the feeding amount for larvae showed a “low-high-low” trend during the breeding period, and the highest feeding amount was observed between Zoea Ⅴ and the megalopa stage. Although the seedling yield of single crab in Size Ⅰ was significantly higher than that of Size Ⅱ, the per unit area yield was significantly lower in Size Ⅱ broodstock, and the dilution ratio was also relatively lower in Size Ⅱ broodstock. In conclusion, although the super-sized broodstock exhibited significantly higher broodstock quantity and individual seedling yield compared to the small-sized parental stock, the super-sized parental stock demonstrated lower broodstock incubation rate, survival rate, and dilution rate compared to the small-sized broodstock. Further research is needed to explore how nutritional regulation can be utilized to enhance the reproductive performance of super-sized broodstock.