A Fourier transform ion cyclotron resonance mass spectrometry(FTICR-MS) with cluster analysis and principal components analysis(PCA) was developed for the identification of chemical constituents in Ganoderma lucidum and the analysis of its fingerprintings used for origin differentiation.The Ganoderma lucidum samples were extracted with a reflux using 50% methanol as solvent

then analyzed directly by FTICR-MS.The MS spectra were recorded at m/z 100-1 000 Da with ESI source under a negative ion detection mode.The chemical constituents in Ganoderma lucidum were identified by accurate mass determination in MS/MS experiments

and total of sixty-three active ingredients

including one terpene aldehyde

three sugars

four triterpene alcohols

six organic acids and forty-nine triterpene acids

were identified by comparing their mass spectrometric inforamtion with those of reference compounds and literatures.The Ganoderma lucidum samples derived from different origins were distinguished by cluster analysis and PCA

and a good origin differentiation was obtained under 95% confidence interval.Experimental results showed that the developed method could be applied in the rapid

direct and efficient analysis of Ganoderma lucidum and its fingerprintings

and was a promising approach for analysis of traditional Chinese medicine.