Abstract: On the bases of experimental data of the compaction of various powders, comparisons and analyses of two methods for varifying the powder compaction equation proposed by Kawakita and its accuracy have been made by using statistically analyzing measures and the physical significance of equation parameters and the application range of equation have been discussed. Furthermore, a modified equation is proposed, which is expressed as:log$\left({\frac{{D-{D_0}}}{{1-{D}}}} \right)$=AlogP+B. The results of statistical analyses show that the modified equation gives not only higher accuracy, but also wider applicability.