Abstract: Taking the sixth agricultural division as an example,meteorological conditions between abundant year and lean year for cotton production were analyzed by using the meteorological data from 1981 to 2007,including temperature,accumulated temperature,frost-free period,precipitation and sunshine.The evaluating indexes of meteorological conditions between abundant year and lean year for cotton production were given out.The indexes in abundant year were≥10℃ accumulated temperature of the total year was more than 3600℃,the average temperature in July was higher than 25℃,frost-free period was more than 170 days.The index in lean year were≥10℃ accumulated temperature of the total year was less than 3300℃,the average temperature in July was lower than 24℃,frost-free period was less than 160 days.The main reasons to cotton yields differences between abundant year and lean year were lack of heat resources in the mid-later stage and low-temperature in summer and autumn.The results could provide a reference to cotton cultivation,management and climate assessment.

Key words: Cotton, Cotton, Abundant year and lean year, Key meteorological index, Average temperature and precipitation, Active accumulated temperature