Abstract: The insecticidal efficiency, loosening, comprehensive processing quality, and smoking quality of sliced tobacco block treated with microwave were investigated.The results showed that:1) the insecticidal efficiency of microwave treatment could be up to 100% when the temperature of tobacco was above 65℃;2) over 90% of three types of tobacco was loosened when their temperature was in the range of 40-45℃;3) the smoking quality of lower grade tobacco and cigarettes of economical brands was improved to a certain extent by microwave treatment;and 4) the comprehensive processing quality of tobacco treated with microwave was significantly improved in the loosening and conditioning process step.