Abstract: Impacts of altitude changes on growth and yield of rice as well as photosynthesis characteristics were analyzed based on rice potted and carrying experiment at 4 sites of different altitudes from April to October of 2013 in Dongchuan region in Yunnan province.The critical altitudes which make the maximum differences of rice growth for japonica rice and indica rice were ascertained.The chilling injury indexes of rice at elongation, blooming and fructicative and milk-ripe stages were determined combining synchronous meteorological observation data.The results show that temperature change with increasing altitude influences greatly growth indexes of indica rice and japonica rice and their photosynthesis, especially for japonica rice.The critical altitude of the maximum difference for indica rice growth is from 1500 m to 1800 m, while that for japonica rice growth is from 1800 m to 2100 m.At the jointing stage, the low temperature and chilling injury indexes for indica rice and japonica rice are defined as 19.6℃ and 17.2℃;both are 20.5℃ and 18.1℃ at the blooming and fructicative stage;they are 19.1℃ and 16.7℃ at the milky stage, respectively.

Key words: Rice, Chilling injury, Photosynthesis, Altitude, Carrying experiment