To satisfy the requirements of NdAlO3-CaTiO3 microwave dielectric properties,0.32NdAl(1+x)O3-0.68CaTiO3 ceramics were prepared by the solid state reaction method.The effect of the nonstoichiometry of Al3+ on the property and structure of 0.32NdAlO3-0.68CaTiO3 ceramic for differentx value (x=-0.001,-0.002,-0.003,0,0.001,0.002 and 0.003 respectively).It is found that,the ceramic structure is dense,without pores,grain boundary definition,the components are basically the same X ray diffraction,which is basically the same ingredients,the main phase is 0.32NdAlO3 0.68CaTiO3.Compared with the formula of x= 0,the changes of Al3+ lead to the density and Q×f increase while the microwave dielectric constant (εr) decrease.As x changes from 0 to ±0.003,the density of ceramic materials reached the extreme of 4.841 g/cm3 and 4.884 g/cm3 respectively atx=±0.001.The microwave dielectric constant εr is 45.13 at x=0,and decrease to both sides.The value of reached the extreme of 36 700 and 36 600 respectively at x=± 0.001.