A widely distributed mayfly species Ametropus fragilis Albarda, recorded from Europe to North America and the Far East of Russia and Mongolia, was collected from Ili River (Xinjiang Uygur Autonomous Region, northwestern China). This updated distribution information shows it occupies a large geographic region and more water systems. The species, genus and family, all new for China, have unique and distinct identification characteristics: psammophilous nymphs having extensions on the anterior mesonotum, spinous pads at the base of forelegs and enlongated claws, male imagos with fused penes and two pair of long cubital intercalaries in forewings. However, the phylogenetic position of family Ametropodidae remains unclear although it is generally grouped in the superfamily Siphlonuroidea.