Through extensive collecting, behavioral observation and test of obstructing fig wasps from entering figs, the community structure of fig wasps， the reproductive strategies of non-pollinating fig wasps (NPFW) and the effects of non-pollinating fig wasps on the figwasp mutualism of Ficus cyrtophylla,  an understory fig species in the tropical rain forest of Xishuangbanna, were studied. Except the obligate pollinator-Blastophaga sp. for F. cyrtophylla， there were three non-pollinating fig wasp species in its syconia, i.e., Platyneura sp., Philotrypesis sp. and Sycoscapter sp. In the fig wasp community, Blastophaga sp., as the dominant species, accounted for 92.21% of the total fig wasps， while Sycoscapter  sp. accounted for only 5.78%， Philotrypesis  sp. 1.84% and Platyneurasp. 0.17% of the total fig wasps. Sycoscaptersp. was the primary non-pollinating fig wasp. All these non-pollinators oviposited outside the figs, and they produced their offsprings through co-inhabiting and competing with pollinators for reproductive sites or food resources. Platyneura sp. was the gall-maker while Philotrypesissp. and Sycoscaptersp. were both inquilines. If no pollinators entered the figs，all the non-pollinators would fail to produce their offsprings. The non-pollinators performed some significantly negative effects on the pollinator population size and the number of female pollinators， but not on the number of male pollinating fig wasps, and thus resulted in a significant increase of the ratio of males to the total number of the pollinators. These results show that non-pollinators usually prefer the galls of female pollinators to the galls of male pollinating fig wasps when they oviposit. Because the female pollinators are the only vectors for figs， the non-pollinators may negatively affect the stable existence and development of the fig-wasp mutualism.