Metacnephia pamiriensis Petrova, sp, n, in its genitalia is similar with M. pallipes. It differs in the number (16 rather than 30-60) and branching (arranged in three bundles) of respiratory threads and a peculiar structure of pupal cocoon. Diploid number of chromosomes is 6 (n = 3). Chromosomes are submetacentrical. The peculiarities of polytenic chromosomes are described and results of karyological comparison with M. pallipes given.