A new species, Armascirus jini sp. nov., is described and illustrated. It is similar to A. cerris and A. gimpeli, and can be distinguished by the following features: lateral plates over the level of c1, with fine striation; genital plates triangle-shaped; genital setae g1–g4 unequal in length; leg genu I with 2 sts, tarsus I without tsl; median shield length:width 1:1. The key to the world species of Armascirus is updated.