Abstract: In order to develop a new fresh-keeping technique of eatable lily bulb, the effects of chlorine dioxide (ClO2) treatment on postharvest rots and fresh-keeping of Lanzhou lily bulb (Lilium davidii var．unicolor) were studied during storaged at (-3±1)℃. The results showed that the rot rate significantly reduced after Lanzhou lily bulb was treated with different concerntration of ClO2 for 1 hour. 6 mg/L ClO2 treatment decreased the rot rate to the lowest level，which lowered respiration rate, inhibited the increase of the titration acid content and the malondialdehyde content, and prohibited the loss of vitamin C and soluble sugar, maintained the quality of lily bulb. The fresh-keeping effect was decreased if treated by lower or higher concentration of ClO2.These data suggest that ClO2 treatment(6 mg/L) may be used as preservative in the practical application of lily storage and transportation.