Abstract: In a plane rectangular coordinate system, mathematics simulation of the change of moisture content in a corn kernel during tempering is presented by the finite element method. The corn kernels are dried for 2 hours at 75 ℃ heated air temperature, and put into a vacuum box to keep temperature. The results indicate that the moisture content in the center of the kernel during tempering slowly decreased with time, the outer portions of the kernel rapid remoistened, but small increased in moisture near the surface. In a corn kernel, the average moisture content of soft endosperm slowly decreased, and the others of horny endosperm and germ increased with time.