The analytical method of free aroma components in Pu-erh tea was investigated;the change and the corresponding reasons of target components during pile-fermention processes were discussed.First,qualitative analysis in Pu-erh tea was carried out by comparing with standard materials and determined with GC-MS.Then,using ethyl decylate as internal standard,the quantitative analysis of the components was conducted by GC.The results had higher repeatability and accuracy.Second,the contents of free aroma components in samples of different piled-fermentation processes were determined by the constructed method.It was found that the contents of high-volatile components were decreased with prolonging of time during pile-fermentation process.However,linalool was increased to the maximum value at the end of second pile-fermentation.This may be relevant with the high content of linalool glycoside in tea samples.The contents of 1,2,3-and 1,2,4-trimethoxylbenzene were different from the high-volatile one.They are,in overall,increased during pile-fermentation process,and got to the maximum at the ends of the second and third piled-fermentation.This is probably correlated with the intensity of the combining action of mycete and saccharomycete,which accelerated the process of methylation reaction.