A new eutardigrade, Isohypsibius archangajensis sp. nov. is described from a moss sample collected in Mongolia. The new species is similar to I. barbarae Pilato et Binda, 2002 and I. undulatus Thulin, 1928 but it differs from them by the presence of shallow depressions forming the reticular design on the dorsal and lateral cuticle, lower number of dorsal undulations, larger body size, stylet supports inserted on the buccal tube in more caudal position, wider buccal tube and longer placoids.