Abstract: With tobacco cv. Yuyan12 as material， the activity of roots system， protective enzymes， Cd content in tobacco leaves and changes of leaf biomass with the application of biochar and different fertilizers under Cd stress were explored by pot experiment. It was shown that addition of biochar could increase soil rhizosphere pH， and the contents of available Cd in soil and tobacco leaves were decreased significantly at fast growing period （60 d）. At mature period （90 d）， for the fertilization method of compound fertilizer or compound fertilizer with organic fertilizer， the content of available Cd in soil was reduced by 22.2% and 7.14%， respectively， after addition of biochar， and Cd concentration in tobacco leaves was reduced by 61.3% and 40.3%， respectively. Meanwhile， the activity of root system was increased by 11.24 and 18.85 μg·g-1·h-1， respectively， and the biomass of tobacco leaves was increased by 67.6% and 21.4%， respectively， for these two treatments after addition of biochar. Under Cd stress， after addition of biochar into these two fertilization methods， the content of MDA decreased significantly， and the activities of SOD， POD and CAT of tobacco leaves were increased. Therefore， for the fertilization method of organic fertilizer and compound fertilizer， the addition of biochar could effectively decrease Cd concentration in tobacco leaves， and eliminate Cd stress.

Key words: biochar, fertilizer, tobacco, Cd concentration ；available Cd, protective enzyme