Abstract: The inhibition bioactivity and the induced resistance of ornamental lily to Penicillium cyclopium elicited by three chemicals were tested. The results showed that the inhibition effects of salicylic acid (SA), nanometer silicon and ammonium chloride to P. cyclopium were very weak, and the rates of inhibition were less than 5.6%. When treated at the concentration 100 μg/ml, 50 μg/ml and 25 μg/ml of salicylic acid (SA), the induced resistance to lily bulb reached to 79.09%, 69.28% and 61.91%, respectively. When lily bulbs were treated with 100 μg/ml of three chemicals and then inoculated with P. cyclopium, the enzyme activities of POD, PAL and β-1,3-glucosan enzyme of lily bulbs were higher than those of the control. As ornamental lily bulbs treated with the concentration of 100 μg/ml of three chemicals and stored at 2 ℃ for 4 months, the disease incidence and index of the disease of ornamental lily caused by P. cyclopium were lower than those of the control. The induced resistance to lily bulbs, elicited by the three chemicals, reached to 60.89%, 55.56% and 35.31%, respectively. Correspondingly, the treated lily bulbs sprouted normally and the sprouting rates of lily bulbs were 91.67%, 90.83%, 90.83%, respectively. The results indicated that the induced resistance by these three chemicals could control P. cyclopium infection in lily bulbs.