Bamboo charcoal was selected as the principal carrier, and chitosan and sodium alginate as the secondary carrier for the immobilization a degradation bacterium which was isolated from activated sludge. The growth of immobilized microorganism on bamboo charcoal and atrazine degradation in soils were investigated. The results showed that bamboo charcoal had a large capacity of immobilized microorganism. The smaller the particle size of bamboo charcoal, the more the microorganism immobilized. The strains grew well on bamboo charcoal, and reached logarithmic phase at 48 h. Chitosan and sodium alginate were used for cross-linking microorganism on bamboo-charcoal, which enlarged the space for the cell growth, significantly increased the biomass of bacterium. 1% chitosan + 5% sodium alginate + bamboo charcoal were suggested for the optimum formulations of microorganism immobilization. The degradation rate of atrazine in soil was larger significantly when adding immobilized microorganism by bamboo charcoal. After 28 d, the residues of atrazine in vertisol and red soil were 48.07% and 47.23%, respectively.