The Cu2ZnSnS4 (CZTS) thin films were successfully prepared on glass substrate by pulsed laser deposition (PLD) using CZTS target. The laser incident energy was varied from 3 J·cm-2 to 6 J·cm-2 at the interval of 1 J·cm-2, and its influence on chemical composition, crystal structure, morphology and band gap of CZTS thin films was investigated by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), atomic force microscopy (AFM) and ultraviolet-visible-near infrared (UV-Vis-NIR) absorption spectra, respectively. The result of EDS indicated that these CZTS thin films were Cu-rich and S-poor. The XRD study showed CZTS thin films exhibited strong preferential orientation of grains along [112] direction. The band gap of CZTS thin films was 1.72, 1.37, 1.25 and 1.11 eV corresponding to incident laser energy of 3, 4, 5and 6 J·cm-2