The year of 2013 is a typical rainy and poor sunshine year, and the monthly sunshine hours from May to October were all lower than the average, which from July to September was only 69.3%,71.1% and 56.2% of average, respectively. In cotton-wheat system 10 cotton varieties （lines） were planted to select the most suitable varieties for cotton-wheat system in rainy and poor sunshine years through investigating cotton growing traits in 2013. The results showed that in cotton-wheat system the vegetative growth of cotton was mainly from late June to middle July especially in rainy and poor sunshine years. And with the increase of the cotton growth period the peak of vegetative growth delayed, the ratio of the autumn bolls increased, and the ratio of pre-frost yield decreased. In all the varieties unginned cottonyield of Zhongmiansuo 50 with shorter growth period, higher rate of summer bolls and better fiber quality, seed yield reached 3 814.1 kg/hm2, higher than that of other varieties （lines） significantly, and the rate of pre-frost yield reached 83.4%, which was the most suitable variety for cotton-wheat system in rainy and poor sunshine years.
