Abstract: Xyelia lii new species Female:Head dark yellow; antennae dark brown;palpi yellow;ocellar area and its hind part,two kidney-form spots between eyes and ocelli,occiput,brownish black;two fine lines on lateral sutures,two oblique lines from lateral ocelli to antennal sockets,light brownish black.Thorax black;most part of prescutum,inner side of scutum,anterior part of scutellum,deep yellow;legs reddish yellow. Abdomen black;ovipositor black. Antennae and maxillary palpi as fig.1,2.Clypeus with central part convex and with central part of front margin convex as lobe; antennal furrows distinct;lateral sutures obsolete,transverse surture and coronal suture distinct;hind margin of head almost straight;venation of forewing as fig.3.Head with numerous fine punctures and sculptures(40×);thorax with numerous fine punctures.POL OCL=0.14:0.18;ovipositor as fig.4.Measurements(mm):Head 1.04; antennal joint 2 plus joint 3 0.83;length of forewing 4.03;length of pterostigma 1.02;width of pterostigma 0.39;length of body 3.32, including ovipositor 4.83;length of abdomen 1.47;length of ovipositor 1.52;lateral width of ovipositor 0.21;dorsal width of ovipositor 0.21;dorsal width of ovipositor 0.08. Male:Hypopygium deep yellow;POL:OCL=0.16:0.16;width of head 1.04;length of antennal joint 2 plus 3 1.04;forewing 4.24;length of pterostigma 0.90;width of pterostigma 0.39;length of body 3.32. The rest color and structure same as female.Penis valve as fig.5. Holotype:female,Jiangsu Province (Nanking),18,3.1984;Li Shangshu leg;Allotype:male,same as holotype;Paratypes:3♀♀,3♂♂ same as holotype. This new species is related to Xyela japonica Rohwer,but is easily distinguished from the latter by the dark yellow head,the width of head being over the length of antennal joint 2 plus joing 3,the light yellowish white pterostigma,the central part of clypeus which has no small tubercle. The adults feed on the pollen of Salix babylonica. All the type specimens are deposited in the collection of the Forest Research Institute,the Chinese Academy of Forestry.