To reveal the influence of long-term straw mulching and no tillage (NT) on soil structure and soil and water conservation of Mollisols sloping farmland, two 14 years long-term experiments, including NT and conventional tillage (CT), were conducted to compare soil structure, water conservation capacity and soil retention effect. The results showed that compared with CT, the soil bulk density of NT did not increased significantly (P>0.05). The total porosity and non-capillary porosity of NT were lower than those of CT in 0-20 cm layer, while NT increased the capillary porosity and content of water stable aggregate (WR_0.25), and the differences in WR_0.25 and mean weight diameter of soil aggregate (MWD) between the two treatments were significant (P<0.05). Meanwhile, NT increased the initial infiltration rate and stable infiltration rate of ridge platform by 28.8% and 24.7%, respectively. And in 0-10 cm layer, the differences in saturated water content and field capacity between the two treatments were significant (P<0.05). In addition, the number of runoff production, runoff and soil loss decreased by 11 times, 86.6% and 98.9% in NT, respectively. This study indicated that long-term continuous NT was an effective practice to stabilize soil structure and prevent soil erosion in Molliosls.