Abstract: Ketones,phenols and their derivatives(referred as KPs) were extracted from natural plants with ultrasonic-organic solvent technology.Stable porphyrin compounds,HPs,were made from the haematochrome extracted from fresh animal blood with acidic acetone.And then a complex biochemical agent was prepared.By taking tea powder as a carrier,a dual filter was made and applied in filter cigarette manufacturing.The test results showed that:comparing with the control, the contents of polycyclic aromatic hydrocarbons,tobacco specific N-nitrosoamines,free radicals,aromatic amines,and other harmful components in mainstream smoke of cigarettes with the dual filter were reduced significantly.The mechanism of harmful component reducing of complex biochemical agent was also discussed.