The diagnosis of Bionychiurus Pomorski, 1996 is updated and a identification key to the world species of the genus is given. A new species, B. changbaiensis sp. nov., as the first Chinese species of the genus, is described from Northeast China. The new species is diagnosed by pso formulae as 32/133/33343 dorsally and 11/000/01120 ventrally, psx present on subcoxa 1 of legs I, II and III as 1,1 and 1 respectively, PAO composed with 22-26 granulated vesicles, Th. I with 9-10+9-10 chaetae dorsally, chaetae on subcoxa 1 of legs I-III as 5/6/6, unguiculus 0.8 times as long as inner edge of unguis and anal spines as long as inner edge of hind unguis.