Abstract:Based on the field plot observation and related meteorological data, the effects of climate change in 1985〖KG-*2〗-〖KG-*7〗2005 on the growth and development o f subalpine meadow Poa botryoides in Maqu County of Gansu Province were analyzed . The results showed that during study period, the annual precipitation in the Maqu County had a decreasing tr〖JP2〗end, with a rate of -9895 mm·(10 a)-1 and a cyc le of 3 years, while the annual air temperature had an increasing trend, with a rate of 0341 ℃·(10 a)-1. The aridity index of P. botryoides in grow th season had an obvious increasing trend, with a rate of 0036 ·(10 a)-1 , and the tendency was more markedly from the beginning of the 1990s to 2005. The pe riod from reviving to ripeness of P. botryoides was 140〖KG-*2〗-〖KG-*7〗150 d, and the requirements of accumulated temperature above 0 ℃, precipitation, a nd sunshine duration in this period were 1000 ℃〖KG-*2〗-〖KG-*7〗1200 ℃, 400〖KG-*2〗-〖KG-*7〗450 mm, and 1000〖KG-*2〗-〖KG-*7〗1100 h, respectively . The growth rate of P. botryoides turned to higher at 54 d after reviving, reached the highest at 80 d after reviving, and became lower at 104 d after revi ving. Under the effects of climate warming, the phenophase of P. botryoides was advanced by 15 d·(10 a)-1 at heading stage, 7〖KG-*2〗-〖KG-*7〗8 d·(1 0 a)-1 at flowering stage, 8〖KG-*2〗-〖KG-*7〗9 d·(10 a)-1 at ripenes s stage, and 3 d·(10 a)-1 at withering stage. Climate change made the P. botryoides yield in study area have greater variation and higher unsteadiness.