Abstract: The effects of conservation tillage and straw application on the soil microorganisms and P-dissolving characteristics were studied．The results show that minimum tillage has a good effect on the microbial carbon，zero tillage and straw application can increase the ergosterol level and accumulation of organic-C in soil．The soil organic-C levels have no significant differences in different tillage modes ．Straw application can increase the soil organic-C content，zero tillage can increase the population of soil microorganisms，deep tillage shows a lower po pulation of soil microorganisms．The microrganismamount of straw application is significantly higher than that without straw application．M inimum tillage have a higher poPulation of soil micro rganisms，zero tillage shows a lower po pulation of P-dissolving microrganism ，minimum and zero tillages promote the development of high efficient P-dissolving strain．Crop residues can enhance the po pulation of phosphate solubilizing micro rganism ，and development of higher efficient strain of P solubilization．