Abstract: The stability of the botanical insecticidal components Celangulin V,Celangulin I,NW 28 and NW 53 in three buffer solutions with different pH values at 54℃±1℃ for 24h was studied by high performance liquid chromatography. Celangulin V,Celangulin I and NW 53 were more stable in pH 4 buffer solution,while NW 28 was less stable,the hydrolysis rates of them were 5.03%,4.15%,6.60% and 19.75%,respectively. The stability of four tested compounds in pH 7 buffer solution exhibited similar trend with that of above metioned,and their hydrolysis rates were 6.43%,12.50%,12.03% and 50.55%,respectively. Whereas in pH 10 buffer solution,all tested components were hydrolyzed easily,and their hydrolysis rates were 71.53%,84.55%,77.68% and 99.30%,respectively. The hydrolysates of Celanlulin V were also investigated by means of HPLC-ESI-MS/MS. The results showed that the main hydrolysates were produced from the break of varies ester bonds substituted at C-1,C-2,C-8 and C-9 of the β-dihydroagrofuran sesquiterpene skeleton,in which the structures of five compounds were deduced by their MS/MS spectra.