Abstract: The Portland cement and high calcium fly ash samples(shortened form P.C. and HCFA)which have different particle size distributions were mixed in a proportion of 50 : 50. The mortar strength of HCFA cement in 3 and 28 days were tested. The particle size distributions of samples were tested by LS－230 and Rosin－Rammler. Origin software is used to make tri－dimension picture, in which macro property was enacted as z axes, the difference between character diameter De of P.C. and HCFA enacted as x axes, De of HCFA － P.C. mixing sample enacted as y axes. The relationship between the development trend of macro property and the difference between De of P.C.and HCFA and De of mixing sample are given. The best particle size distribution matching P.C. and HCFA was given.
