Pesticide pollutions have become increasingly severe. Especially the extensive production and application of chlorpyrifos have resulted in the environmental pollution and ecological damage. The employment of the immobilized microorganism degradation of chlorpyrifos in soil is a kind of effective technology without secondary pollution. The best ratio of immobilized carrier has been determined by comparison among different carriers for chlorpyrifos degradation. Based upon the adoption of Bacillus LLBD4, pH value, temperature and initial concentration of chlorpyrifos were studied in this experiment. The results showed that the combination of 10% of PVC, 1% of activated carbon and 0.5% sodium alginate can be served as the best carrier, furthermore, chlorpyrifos degradation efficiency reached the peak when the pH was set to 7.0, the initial concentration of chlorpyrifos was 100 mg·L-1at 30°C, reaching about 83%.