Abstract: Results of storing mass propagated parasitoid Encarsia formosa by placing the parasitized mummy pupae (the black scale) of its host Trialeurodes vaporariorum under the temperatures of 3, 8, 1O and 12℃ for 15, 20, 25, 3O and 35 days indicated that the emergence rate of the parasitoid was possitively correlated with the storage temperature, and negatively correlated with the length of storage duration. Storage under 12℃ for 2O days resulted in 87% emergence of the parasitoid, which waa not srgnificantly different from that of the non-stored black scales in the control. , Storing the black scale on their host plant leaves produced a higher parasitoid emergence rate than that without the plant leaves. Although the developmental stage of E. formosa at the beginning of storage did not show any obvious effect on the adult emergence rate, some of the parasitoid of more than three-day old emerged within 2O days during storage. Storage over 20 daya had an unfavorable effect on the fecundity and longevity of the adult, as the fecundity was 48% lower than that in the control, and the longevity was reduced from 18.9 days to 13,8 days. Storing newly emerged adult parasitoid under 12℃ for 5 days had a low mortality of 2%. The fecundity of the adults, however, was 76% lower than that in the control.