To research the effect of continuous cropping on cotton soil microorganisms and soil microorganisms on grow of cotton, we studied the total numbers of aerobic self-nitrogen-fixing bacteria, potassium bacteria, cellulose decomposing bacteria, phosphate solubilizing bacteria, organic-phosphorus-dissolving bacteria distributed in continuous cropping cotton fields of regimental farm 2 and 3 of the first agricultural division through dilution spread plate method. Results showed that the total numbers of five kinds of bacteria was highest in blooming and bolling periods, lowest in seeding periods and higher in before sowing periods. The total numbers of five kinds of bacteria was no notable regular changes with continuous cropping year. The numbers of aerobic self-nitrogen-fixing bacteria at different cotton growth stages in regimental farm 2 was higher than in regimental farm 3 and the numbers change of other bacteria was varied in different cotton growth stages in regimental farm 2 and 3. Soil beneficial bacteria were negatively correlated with a variety of soil nutrient ion and free-living nitrogen fixing bacteria were significantly positive correlated with soil total nitrogen.