The moss flora was explored above timber line in Kostin & Balkhach Mts. in the elfin wood formed by Pinus pumila and Duschekia fruticosa and in alpine belts. Annotated list of 179 species is provided. Five species are new to Kamchatka (Encalypta procera, Pseudohygrohypnum subeugyrium, Schistidium obscurum, Stereodon fauriei, Tayloria froelichiana) and many rare species are also found in this area, including Blindia acuta, Cnestrum schistii, Ditrichum heteromallum, D. pallidum, Encalypta affinis, E. alpina, E. brevicolla, Mielichhoferia mielichhoferiana, Orthothecium strictum, Tortella alpicola, etc.