Abstract: In the present paper，a new species of the genus Goniozus，a parasite of clearwing moth (Lepidoptera，Sesiidae)，is described．Goniozus sinicus n．Sp.Female(alate):Length 3.3mm；fore wing 2.1mm．First 4 antennal segments in a ra rio of about 15:7:6:6．Head almost square；WF 1.2x HE,OOL 1.83x WOT．Black，shining; mandibles reddsih brown；antennae，trochanters，tibiae and tarsi yellow to brownish yellow；coxae and femora pitchy；claws dark brown．Wings hyaline，prostigma and Stigma brown，veins yellowish white．Mandibles with 3 apical teeth distinctly．Posterior ocelli nearly touching vertex crest．The tergum of propodeum with a V-Shaped median carina Head，thorax and propodeum coriaceous from which pronotum is somewhat smoother and there is some fine longitudinal lines on propleura；abdomen smooth．(figs．1-4) Male(alate): Length 2.5mm；fore wing 1.7mm．First 4 antennal segments in a ratio of about 13:6:5:5．LH O.95x WH； WF 1.14x HE；OOL 2.42x WOT．The coloration and structures of the body similar to the female．Host:Synanthedon castanevora Yang et Wang Holotype：♀，Qianxi County of Hebei Prov.，10 V 1986，Liu Huiying leg；Allotype：♂，same data as for holotype；Paratypes：7♀♀，same data as for holotype．All the types are deposited in the Insect Collections of the Forest Research Institute，the Chinese Academv of Forestry，Beijing，China．The new species resembles G．Japonicus Ashmead in most particulars，but differs from the latter in nO fine longitudinal line s on the sides of propodeum and diffe rent ratios of the head．