Abstract: In order to elucidate the mechanism of the influence of vitellinogen gene on the reproduction and embryonic development of Daphnia, the changes on the expression of vitellogenin gene and the number of offspring of D. sinensis under RNA interference (RNAi) was studied. After RNA interference, compared with the EGFP (Enhanced Green Fluorescent Protein) group, there was no significant difference in number of offspring at the first reproduction or relative expression level of Vtg gene of D. sinensis in the Vtg group at the 2% E. coli concentration. At the 5% E. coli concentration, the number of offspring at the first four adult instar in the Vtg group were significantly lower than those in the EGFP group. Additionally, the relative expressions of the Vtg gene of D. sinensis at the first and the fourth adult instars in the Vtg group were significantly lower than those in the EGFP group, with decreases of 5.25% and 78.03%, respectively. In addition, the phenomenon of embryonic digestion and underdevelopment of offspring also appeared in the Vtg group after RNAi. The results suggest that high-intensity and prolonged RNA interference can significantly reduce the relative expression of the Vtg gene in D. sinensis, leading to a marked inhibition of reproductive capacity and embryonic development. Therefore, the Vtg gene plays an important role in the reproduction and embryonic development of D. sinensis.