The field experiments were conducted at Yuli county of Xinjiang in 2004 from Apr. to Oct. It is tound that in south Xinjiang, in cotton seedling stage, because of covering the function of the membrane, the salt in soil begin the dividing area, the salt is gathered strongly in 0-20 cm in uncovered area, and the salt of soil under film had taken place side direction transport and move to the uncovered area which have aggravated the salt of uncovered area even more. After cotton growing stage finishing, the salt of 0- 60 cm layers have increased, and assembled sharply in the uncovered area in 0-20 cm layers; The salt of lower water treats enhanced greater,the ration of salt accumulation reached 94.5%,which mainly come from the salt that moving up water carried on, up to 57 % of increased salt,and the salt increased of higher irrigation treats mainly come from the salt irrigation water carrying on, was about 81%, so adding irrigating water can decreased the accumulation of salt in a certain extent.