We report the fabrication of Co-doped ZnO thin films prepared by Pulsed Laser Deposition (PLD) on glass substrates by Nd-YAG Q-Switching second harmonic generation (SHG) Pulsed Laser with a wavelength of 532nm, repetition rate of 10 Hz and pulsed width 10ns. The effect of doping on the structure properties of the ZnO:Co films have been investigated by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). The result showed that polycrystalline and (100)-oriented pure ZnO films were obtained at all substrate temperature of (200°C and 400°C), laser fluence (0.4) J/cm2 and the ZnO films grown at 4000C. X-ray diffraction (XRD) analysis demonstrates that the ZnO thin films with Co of (1, 3 and 5) wt.% have a highly (100) preferred orientation with only one high intense diffraction peak with a full width at half maximum (FWHM) less than 0.3°. The smallest grain size was obtained at scanning electron microscopy (SEM) in case of doping compared by grain size of XRD, while the polycrystalline grain size increased from 32.7 nm to 43.5 nm for pure ZnO films.