Abstract: The essential oil in Hangzhou white chrysanthemum was extracted with simultaneous distillation and solvent extraction. The volatile constituents in the oil and its pyrolytic products at 300℃, 600℃ and 900℃, were analyzed by GC/MS and PY-GC/MS. The oil was added into cigarettes as a flavor. The results showed that:1) 52 volatile constituents were identified in the oil, and most of them were monoterpenes and sesquiterpenes; 2) 78, 89 and 94 volatile constituents were identified in the pyrolytic products at 300℃, 600℃, and 900℃, respectively; 3) some of the identified constituents existed both in the oil and its pyrolytic products, some existed only in the oil or in its pyrolytic products; the constituents and their concentrations in pyrolytic products changed with pyrolytic temperatures; 4) the essential oil could improve and modify the flavor of cigarette smoke, enhance the notes of fresh aroma, and reduce its irritation. The essential oil of Hangzhou white chrysanthemum can be used as a cigarette flavoring.