Statistical analysis employing the set of the steric constants Omega(j,k)(R-c) is shown to be very effective in characterizing the substituent steric effect on organic reactions. Omega(j,k)(R-c) contains several variable parameters which are useful for the diagnosis of the character of steric effect. The parameters controlling the angular, or directional, weight (j, k) and the size of reaction center atom X(R-c) are varied in order to elucidate the characteristics of several steric substituent constants.