A method for determination of alkylphenol in Ginkgo sarcotesta was developed on the basis of thermochemolysis-GC.200 μg of sarcotesta powders and 1μl of the trimethylsulfonium hydroxide (TMSH, 0.2 mol/L) methanol solution were added to a small platinum cup.The sample cup was first mounted on the waiting position of the pyrolyzer near room temperature, and then dropped into the heated center of the pyrolyzer maintained at 300 ℃ under the flow of *nitrogen cartier gas.The column temperature was initially set at 50 ℃ and then programmed up to 250 ℃ at a rate of 10 ℃/min, maintained at 250 ℃ for 10 min and then programmed up to 260 ℃ at a rate of 2 ℃/min.DB-23 capillary column (30 m × 0.25 mm i.d.) coated with 50% cyanopropyl-50% dimethylpolysiloxane, 0.25 mm film thickness were used.Two kinds of ginkgols and seven kinds of ginkgolic acid were identified as their corresponding methyl derivatives.On the obtained pyrogram, chemical composition of the alkylphenols in sarcotesta was determined with the relative standard deviation of ginkgolic acid GA17∶2 was less than 7.8% and other alkylphenol was less than 6% for three repeated runs.