Abstract:  Based on orthogonal design method,the orthogonal list L24(61×41× 23) was selected for arranging test,the influences of the quantity of pozzolan ic admixture,the ratio of powdered slag and flyash,the fineness of powdered sla g,and the quality of flyash on the flowabilities,the compressive and flexural s trengths of cement mortar at ages of 7,28,90 and 180 days,respectively,were expl ored.On the basis of experimental tests,the optimum combination of cement,powder ed slag and flyash was determined. The test results showed that the cement morta r containg powdered slag and flyash is better than that only mixing with eithe r powdered slag or flyash.