Before opening the traffic and after the constmction of cement concrete pavement slab, the ce- ment concrete pavement slab may produce the early cracking, when the deformation of the temperature and moisture change is restrained; the slab stress exceeds the concrete tensile strength. Research founds that base play significantly effect on the early pavement cracking. Basing.the early cracking mechanism of the cenent concrete pavement slab and temperature data measured in the early72 horns of cement concrete pavement slab that is constructed in the evening and in the morning, this paper discusses the base parame- tens impact on pavement early cracking and proposes the corresponding prever山ve measures.