The reproductive characteristics of Tamarixa lyciumi Yang, a parasitioid of nymphs of Paratrioza sinica Yang & Li, were studied under laboratory conditions. Sexual reproduction in T. lyciumi occurs much more often than parthenogenesis, which produces only male offspring. The sex ratio is 1.80∶1. Environmental conditions had a marked influence on development, longevity and fecundity. Temperature had the greatest effect; increasing temperature shortening the developmental period. The low temperature threshold of development from egg to pupa is estimated to be 8.22℃ respectively, and the effective accumulative temperature from egg to pupa is 217.21 degree days. Adult longevity decreased with temperature from 15℃ to 35℃. Fecundity was highest at 25℃ and lowest at 35℃. Adults provided with 20% honey water were the most fecund; those provided with 20% sucrose water were the next most fecund. Although providing water prolonged adults life span it did not increase their fecundity. There was no significant difference in the number of progeny per female at 5℃ over 15 days. The emergence rate decreased markedly if pupae were kept at 5℃ longer than 15 days, however, the life span of adults from pupae kept at 5℃ for up to 30 days was not significantly different to the control, nor was there any difference in female fecundity between females that emerged from these pupae and the control.