Agrilinus monikae sp. nov. from Gansu, Qinghai and Sichuan (China) is described and its diagnostic characters are illustrated. The new species is compared with similar and probably closely related complex of the following species: Agrilinus lungaiensis (Petrovitz, 1962), A. pseudolungaiensis Mencl et Rakovič, 2012, A. surdus (Boucomont, 1929) and A. wassuensis (Petrovitz, 1962).
The differential diagnosis is based mainly on different structure of dorsal surface and on the shape of aedeagus. Life history of the new species is tied with excrements and burrows of Ochotona sp. (Lagomorpha) and Marmota himalayana (Hodgson, 1841) (Rodentia).