Abstract: The photosynthesis, dark respiration and soil respiration of plant community in Kobresia humilis meadow were studied from 1990 to 1992 at the Haibei Research Station of Alpine Meadow Ecosystem, Menyuan County, Qinghai province. The characteristics of photosynthesis were measured using Infrared Gasanalyzer (IRGA). The results show that the diurnal variation of net photosynthesis was not obvious in June, but the midday depression appeared in July and August. the photosynthesis of plant community in K. humilis meadow was affected by rather low photosynthetic area index and by the light received by canopy leaves. It had obvious light saturation. The light compensation point and the light saturation point were lower, relative to the photosynthetic activity radiation (PAR) of full sun, which assembles the light response of the single leaves. The soil respiration of uncovered ground and the dark respiration of plant-soil system were not only influenced by temperature, but also related to soil water content and precipitation. The main factors of influencing the photosynthesis character of meadow community were. the strong radiation in plateau region, the lower photosynthetic area index and the turf structure due to the tight combination between plant roots and soil of K. humilis meadow.