In the laser marking process system, a liquid crystal display (LCD) was used as the image mask, which can display dynamically and flexibly the various images by the programmable control. A nanosecond pulsed laser (1064nm) was applied to investigate the characteristic of laser photolithography fabrication technology. The light modulation function of LCD mask was firstly discussed by theory. By observing the graphics morphology with a high-powered optical microscope, it was found that the graphics of laser marking with LCD mask shows that its edges were not ablated but its line inside was ablated. According to analysis, the reasons of this phenomenon are due to the opaque lattice effect and the high light transmittance of black pixel. Results showed that the light modulation function of LCD mask was decided by adjusting the light transmittance with controlling the pixel voltage and a complete graphics was ablated in the range of 0.6J/cm2 ~ 0.8J/cm2.