The Tibetan alpine grasslands, sharing many features with arctic tundra ecosystems, have a unique non-growing-season climate that is usually dry and without persistent snow cover. Pronounced winter warming recently observed in this ecosystem may significantly alter the non-growing-season carbon cycle processes such as soil respiration (R s ), but detailed measurements to assess the patterns, drivers of, and potential feedbacks on R s have not been made yet. We conducted a 4 year study on R s using a unique R s measuring system, composed of an automated soil CO 2 flux sampling system and a custom-made container, to facilitate measurements in this extreme environment. We found that in the nongrowing season, (1) cumulative R s was 82-89 g C m À2 , accounting for 11.8-13.2% of the annual total R s ; (2) surface soil freezing controlled the diurnal pattern of R s and bulk soil freezing induced lower reference respiration rate (R 0 ) and temperature sensitivity (Q 10 ) than those in the growing season (0.40-0.53 versus 0.84-1.32 μmol CO 2 m À2 s À1 for R 0 and 2.5-2.9 versus 2.9-5.6 for Q 10 ); and (3) the intraannual variation in cumulative R s was controlled by accumulated surface soil temperature. We found that in the summer monsoon-dominated Tibetan alpine grassland, surface soil freezing, bulk soil freezing, and accumulated surface soil temperature are the day-, season-, and year-scale drivers of the non-growing-season R s , respectively. Our results suggest that warmer winters can trigger carbon loss from this ecosystem because of higher Q 10 of thawed than frozen soils.