In this paper, gamma-crotonlatone (GCL) was tested as an additive to electrolyte solutions of 1M LiPF6 EC:DMC (1:1, vol) for lithium-ion batteries. Smaller volume amount in the order of 10−6 GCL improved the cyclability of MCMB electrode, and decreased the impedance of MCMB/Li cell. The results of cyclic voltammetry show that the GCL has higher reduction decomposition potential at about 2.1V. The surface morphologies and chemistry of the solid electrolyte interphase (SEI) film formed on MCMB electrodes cycled in 1M LiPF6 EC:DMC with and without GCL were studied by SEM, FTIR and XPS analyses, and the results show that a uniform, stable and low-resistive SEI film was formed on the surface of MCMB electrode, which cause the excellent cyclability of electrode.