Abstract: A modified sericite used as polyethylene reinforcing filler is developed by changing sericite squama structure by means of supersonic gas crushing and chemical surface modification. The interface behaviors of modified sericite and polyethylene composite, as well as the effect of filling content of modified sericite on polyethylene mechanical property, have been studied. The results have benefit to the nonmetallic mineral deep processing and the investigation of resin based composites.