Abstract: A proper bacteriostatic agent formula takes key function in the open tissue culture. In this paper, four common bacteriostats (kanamycin, cephalosporin, carbendazim and sodium hypochlorite) were added to culture mediums separately and the effects of them on tobacco growth status were observed. The results showed that bacterial contamination would be less than 10% when 50 mg/L cephalosporin was added to the medium, while fungi contamination would be less than 10% when carbendazim in 600-fold dilution (50%WP) was added. What爷s more, bacterial and fungi contamination were both less than 10% when culture mediums contained only 1% sodium hypochlorite, and the tobacco explant differentiation was the best. Kanamycin was not a appropriate bacteriostatic agent for open tissue culture of tobacco.