The HfCx absent solid solutions are formed easily resulting from C absence when HfC is being prepared or used. To forecast HfCx macroscopical properties, the valence electron structure of the absent solid-solutions with different x value was analyzed based on solid and molecule empirical theory (EET), and compared with that of the HfC matrix. The results shows that with the decrease of x value, i.e. the increase of the carbon atom absence, the crystal cell constant of the HfCx solid solutions decreased gradually; the number and the bond energy of the max covalent bond and the covalent bond number percent decreased gradually, too. This shows that the hardness, strength, bond energy and melting point were all decreased little by little; while, the toughness, conductivity and sintering properties were improved by degrees.