OBJECTIVE To co mpare the difference of liposoluble constitue nts in different processed products of Huaizhong No.1 Rehmannia glutionsa （fresh R. glutionsa ，R. glutionsa and prepared R. glutionsa ），and to evaluate its in vitro antioxidant activity preliminarily. METHODS Liposoluble extracts were extracted from 3 processed products of R. glutionsa by Soxhlet extraction. Their constituents were analyzed by gas chromatography-mass spectrometry. The spectral library of NIST 98 system was used to automatically retrieve the mass spectrum information of components ，and the structures of compounds were identified in combination with relevant literature and by comparing with eight peak index and EPA/NIH library. Relative contents of the components were calculated by using peak area normalization method with Hewlett Packard software. The antioxidant activities of liposoluble constituents in 3 processed products of R. glutionsa were investigated by 1，1-diphenyl-2-picrylhydrazyl（DPPH）free radical scavenging. RESULTS A total of 79 liposoluble components were identified from different processed products of R. glutionsa，and 48，52 and 37 liposoluble compounds were identified from fresh R. glutionsa ，R. glutionsa and prepared R. glutionsa，respectively；their relative contents accounted for 92.69％，86.29％，92.89％ of the total components respectively. Among them ，there were 20 liposoluble compounds totally ，and their relative contents accounted for 88.73％，80.89％ and 85.87％ of liposoluble components in each processed product respectively ；they were mainly composed of fatty acids such as methyl linoleate，methyl palmitate and methyl oleate. In addition ，there were 18 unique liposoluble components in fresh R. glutionsa ， mostly terpenoids ；there were 17 and 6 unique liposoluble components in R. glutionsa and prepared R. glutionsa ，mostly alkanes. The results of antioxidant experiment showed that median scavenging concentrations of liposoluble components to DPPH limeng free radical were 0.756，0.660，0.758 mg/mL，respectively. CONCLUSIONS The common liposoluble components in different processed products of R. glutionsa are mostly acids；the unique liposoluble components in fresh R. glutionsa are mostly terpenoids ，and those of R. glutionsa and prepared R. glutionsa are mostly alkanes ；the liposoluble constituents possess in vitro antioxidant activities.