Growth behavior and kinetics of grains in a liquid matrix has been studied by computer simulation for various physical and processing conditions. The kinetics of growing and dissolving grains is considered to follow that of single crystals in a matrix. Depending on the crystal shape, i.e. rounded or faceted, different kinetic equations were adopted for growing grains and a single equation was assumed for dissolving grains. Effects of critical parameters such as step free energy, temperature, and liquid volume fraction were evaluated.