Abstract: Mulched with plastic film on the transplanted cottons．the soil temperature in 5cm depth is 0．1～2．98℃ higher than that of unmulched transplanted cottons， the cotton plants grow faster，and the cotton yield is increa sed by 1 1．59％ ～ 1 8．3 1％ ．Before degradable plastic film degrades，the increasing value of soil temperature，which is mulched with double-degradable plastic film and photo-degradable plastic film ，is less higher than that mulched with common plastic film ，and it is higher in sunny days than that in cloudy and rainy days．After the inducing period，the two kinds of degradable plastic film can divided into small pieces，the double-degradable plastic film degrades earlier and faster than another．In the cotton production practice，the common plastic film should be replaced by degradable plastic film ，but the interrelated cultural techniques must be formed．