In the package of infrared device some components made of transparent materials are often needed, dicing and marking such components by using pulse laser are favorite, whereas the processing parameters should be precisely optimized. Targeting on the laser marking of IR grade Conning glass for packaging of infrared focal plane arrays, the essential parameters including ablation threshold, beam features of laser processing head and geometrical error caused by scanning angle, were measured and analyzed. Suitable strategies and parameters for the laser marking process were gained based on the results, and applied to practical operation successfully. Those strategies and parameter setting methods could be extended to the laser marking of other transparent materials.