A method was established for the identification of volatile compounds in recycled and virgin expanded polystyrene（EPS） containers by gas chromatography-mass spectrometry（GC-MS） combined with chemomtrics.The sample was firstly dissolved with dichloromethane

then added methanol to precipitate macromolecular polymer

finally analyzed by GC-MS.Multivariate statistical analysis

including principal component analysis（PCA） and orthogonal partial least squares discriminant analysis（OPLS-DA）

were used to discriminate both virgin and recycled containers

and screen the differential compounds responsible for the discrimination.Results showed that the main constituents in recycled and virgin EPS containers

included polymerization residues（styrene monomer

dimers and trimers）

benzene derivatives and some additives.41 compounds which are significantly different in the two kinds of containers were screened out based on OPLS-DA and t-test

and the discrimination method was improved.This method could be applied in the efficient discrimination of recycled and virgin expanded polystyrene（EPS） containers.