Assuming that the interstellar medium (ISM) is composed of the hot ionized medium (HIM), the warm ionized medium (WIM) and the cold neutral medium (CNM), we examine the interchange processes among them by supernova remnants. These are the evaporation of CNM, the shock heating of WIM and the cold shell formation at the shock front. Calculating the time variation of each component, the timescale and evolutionary characteristics till attaining a steady state are deduced. Generally speaking, the final steady state is classified to two types.