The refined models of residential thermostatically controlled loads (heating, ventilating and air conditioning system and water heater) are built. The regulating and controlling ways of price signal on the models are analyzed in detail. The simulation is implemented in IEEE 13 node typical feeder system under different tariff incentives. The tariff includes the fixed rate, time of use pricing and real time pricing. Changes of load behavior are analyzed under different price signal, and how demand response smooths out fluctuations of distributed generation (DG) are shown. This study demonstrates the performance of demand response, which contributes to gentle the instability of DGs and peak load shifting.