Different kinds of ceramic wastes（sanitary ceramics, exterior wall ceramics and floor tile ceramics） were respectively ground for 8h and 16h by a ball milling to obtain different fineness of each one. Specific surface area, oxide composition and crystal phase were tested. Then the Portland cement was substituted partly with ceramic waste powder at the rate of 20%（by mass）, and the pozzolanic activity of ceramic waste powder was examined according to the Frattini test method and SAI test method. The test results show that all the ceramic waste powders have pozzolanic activity. Pozzolanic activities of sanitary ceramic waste powder and floor tile ceramic waste powder are improved with the increase of the specific surface area of ceramic waste powder. In the ceramic waste powder the alkali reactivity of SiO2 is lower, the reaction between Al2O3 and Ca（OH）2 is the main reason for the pozzolanic activity of ceramic waste powder.