This paper studied the mechanical properties of concrete with cement partially replaced by recycled clay-brick-powder. Four variables (water/cement ratio, sand ratio, replacement level and average particle size of clay-brick-powder) were considered. Each variable had four levels. By using the orthogonal experimental design method, total 17 mixes, including one normal cement concrete as reference, were tested. Experiment results showed that recycled clay-brick-powder could be used as partial replacement of cement in concrete without reducing its properties. The strength was not significantly reduced with cement replacement level up to 25%. The elastic modulus was lower compared with cement concrete.