Abstract: Through the comparison of the allelochemicals obtained from different extracting conditions, it was discovered that extracting time and temperature have important influence on the allelochemicals analysis result. At ambient temperature, more allelochemicals can be obtained with longer extracting time; however, when extracting at 50 ℃, the maximum amount of allelochemicals was obtained at 24 hours, and with the extending of extracting time, the amount of allelochemicals decreased. At high temperature and under high pressure, the amount of allelochemicals was more than those of other treatments except the treatment of extracting for 24 h at 50 ℃. The experiment results indicated that the allelochemicals dessolved faster but became unstable and denaturalized easily at higher extracting temperature. 