A new method for identification of ethylene/alpha-olefin copolymer was established by Fourier Transform Infared (FTIR)-Differential Scanning Calorimetery (DSC) in this article. DSC and FTIR spectroscopy techniques were used to analysis the type and content of alpha-olefin in polyolefine copolymer. FTIR was available to identify the Structures of polyethylene and copolymers of ethylene with different alpha-olefins. The type of polyethylene can be determined by the peak position of 1378 and 1369 cm(-1). According to the peak location of 770, 784, and 895 cm(-1), the type of of alpha-olefin can also be determined. DSC method was used to decide the position of melting peaks. The quantitative investigation of the content of alpha-olefin in polyethylene was Calculated by the formula: -ln(CH2 mol fraction) = -0.331+135.5/T-m. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113:3027-3032, 2009