The soil content in t he mulched gravel-sand layer increased with the elongation of cultivated years of field. There were six t reatments of soil content proportion to gravel sand in the simulating experiment on effect of gravel-sand mulched field degradation to soil temperature and evaporation : t1-5 % , t2-10 % , T3-20 % , T4-25 % , T5-30 % , T6-40 %; two checks : CK1 , pure gravel-sand mulched layer and CK2 , non-mulched layer . The results show that soil temperature in 5 cm and 10 cm depths at 8 :00 and 20 :00 decrease with the aggravation of mulched layer degrading , and appear a transversely placed " S" shape at 14 :00. In comparison with CK1 , the function of delaying t he daily maximum ground temperature weakens as t he deg-radation level increase , companying with daily accumulated temperature decreasing , daily temperature range increasing , and evaporation intensifying. The evaporation rate of CK2 is t hree times as that of CK1 ,but that of treatments T5 or T6 is two times .