The influence of UFPP fiber and polypropylene fiber on improvement of the frost resistance of cement concrete were studied. The results show that the frost resistance of concrete is improved by adding fiber, the frost resistance of concrete with adding UFPP fiber is better than that with adding PP fiber. At the same time, the frost resistance of concrete with adding 0.9 kg/m3 fiber is better than that of concrete with adding 0.6 kg/m3 fiber or without fiber added. Parameters of pore structure were determined. The effect of the frost resistance of cement concrete on pore structure is discussed.