Through the test of compressive strength of specimens after using the new material to replace some particle size of old material,the paper researched the influence of new aggregate replacing old aggregate of some size on the compressive strength of the specimen after forming,and provided the basis for how to effectively improve the performance of old cement regeneration.The results show that to replace the old aggregate of one particle size cannot improve the compressive strength,but when the span of replaced new material particle size became bigger, the compressive strength of material regeneration will be improved.So it is necessary to add some new coarse aggregate to the specimen in the use of new fine aggregate in the process of regeneration.The compared test shows that influence of different particle sizes on cement stabilized base material is less than that of old material.So the norms of cement stabilized base regeneration cannot guide the cement slab regeneration.