Femtosecond laser machining has advantages of wide processing capability and good processing quality due to extremely narrow pulse and high peak energy.In this paper,femtosecond laser is applied to drill small holes on CFRP composite materials using different spot filling patterns.The effect of the partially filling and full filling on the drilling of 3mm holes has been investigated.Optical microscope and industrial CT have been used to measure machining results.The morphology and wall taper angle have been analyzed,and effects of different spot filling patterns on material removal also been compared and discussed.The result shows that full filling pattern can easily form through holes；however,the partial filling pattern can achieve holes with smaller taper angle.The smaller the scanning speeds are,the smaller the taper of the hole is；on the contrary,the higher the scanning speeds is,the greater the taper of the hole is.The filling distance affects the input energy density of the laser,so the filling distance has a direct effect on the depth of the small hole processing,and less effect on the small hole entrance diameter and the small hole taper.