Abstract: Based on the peach orchard planted two years ago, the authors studied the growing effects of peach under the straw mulching treatment. The result indicated that straw mulching could remarkably improve the soil moisture condition and 0~50 cm soil moisture is higher than the control. In each stage, the soil moisture is relevant to the straw mulching under quadratic equation. The weed number, weed dry weight as well as the single weed weight decreased with the increase of straw mulching quantity, and the various ecological indexes mentioned above become the negative exponent with the straw mulching quantity. The correlation coefficient reaches as high as above 0.95. The straw mulched 150 days later, the tree stem and the crown diameter comparatively enhanced with control, the two indexes and the straw mulching quantity present the extremely good correlation under quadratic equation, the correlation coefficient is higher than 0.958. When the straw mulching quantity is smaller than 1.5 t/hm², photosynthesis rate, transpiration rate, stomata resistance assumes the trend of escalation along with the straw mulching quantity increased, when the straw mulching quantity achieved 2.0 t/hm², various physiological indexes decreased but still were higher than the control. Fresh weights and the dry weight of hundred leaves also presented the same regularity.