By the separation and identification of the epiphyte in the air of the plant tissue culture lab,Aspergillus,Mucor,Penicillum,Trichoderma,Rhizopus were found to be the main infective fungi in plant tissue culture. The experiment of mycostatic loop had indicated that sodium hypochlorite and nystatin are good fungistats.The mixture of 50mg/L ketoconazole +50mg/L nystatin +0.1% sodium hypochlorite is the best additive to prevent the fungal contamination in plant tissue culture and has slight damage to plants.