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An analysis is made of the effects of temperature and precipitation on premature senescence of cotton based on the observation data of Huimin from 1988 to 2007 (the data on regular cotton is from 1988 to 1997， and those on insectresistant cotton is from 1998 to 2007).The results show that the number of autumn bells was negatively correlated to the mean temperature from April to July，the higher the mean temperature from May to July， the less the autumn bells， the more serious the premature senescence. If precipitation was less than normal from midJune to midJuly，there occurred seedling weak and premature senescence; while if precipitation was less than normal from midAugust to midSeptember， there occurred less autumn bells and premature senescence. Countermeasures are presented in the aspect of meteorological conditions.