OBJECTIVE： To study and compare the volatile constituents in Forsythia suspensa and old F. suspensa. METHODS： Steam distillation method was adopted to extract volatile oil. GC-MS was adopted to determine the content of volatile oil： the chromatographic conditions： the column was HP-5MS， inlet temperature was 200 ℃， the carrier gas was nitrogen， split ratio was 20 to 1， by programmed temperature， flow rate was 1 ml/min， the injection volume was 1 μl； MS conditions： ion source was electric bombardment ionization source， electron energy was 70 eV， the interface temperature was 280 ℃， ion source temperature was 230 ℃， quadrupole temperature was 150 ℃， electron multiplier voltage was 2 300 V， and mass scanning range was 29-350 amu. RESULTS： The extraction yield order of volatile oil was that F. suspensa heart was higher than F. suspensa， followed by F. suspensa shell and old F. suspensa； there were 18 common peaks in the volatile oil， and the content of β-pinene was the maximum， followed by α-pinene， β-phellandrene， terpinen-4-ol and terpinene； in addition， 4-methylene-1-cyclohexanone， 3-cyclohexene-1-methanol， cumene formaldehyde， 1，7-trimethyl-4-methylenedecahydro， palmitic acid， nutmeg aldehyde can only be detected in the volatile oil of old F. suspensa； while α-phellandrene， ocimene， α-terpineol， α-pinocarvone， cis-piperitol， bornyl acetate， α-cubebene and germacrene D can only present in F. suspensa. CONCLUSIONS： The main chemical components in the volatile oil of F. suspensa and old F. suspensa are basically the same， but there are also some differences. The discovery can provide some basis for the material basic research in the pharmacodynamic differences of F. suspensa.