Abstract: Pyrethrum cinerariifolium Trev. was used as the material to detect insecticidal activity of pyrethrin from hairy roots and callus so as to supply certain theoretical basis for producing pyrethrin by cell engineering. The stems and leaves of Pyrethrum cinerariifolium were taken as explants to induce the callus and hairy roots. Acetone was used to extract pyrethrin and armyworm was selected to test the insecticidal activity by armyworm dipping and leaf dipping method. The results showed that pyrethrin extracted from the callus and hairy roots had insecticidal activity. Its antifeedant activity was better than contact toxicity. The insecticidal activity of pyrethrin from hairy roots was better than that from callus. And the insecticidal activity tested by armyworm dipping method was better than that of leaf dipping method. This study provides a new way for the future industrial production of pyrethrin by cell engineering.