Effects of misorientation of the substrate and growth temperature on the carrier concentration were investigated for the epitaxial growth of GaAs by chloride vapor phase epitaxy (VPE) utilizing the hydrogen reduction method. Carrier concentrations of the epitaxial layers grown on 2° off (100) substrates are always about one half of those on exactly (100) substrates, even though the compensation ratios are the same. The carrier concentration and the total impurity incorporated increase monotonically with increase of the growth temperature, but the compensation ratio is a minimum at a growth temperature of 750°C and increases at higher and lower growth temperatures. These results seem to be explained by the Kossel model, i.e. by a smaller segregation constants of the impurities for 2° off (100) substrates with many growth steps.