Performance of the compression type heat pump has increased greatly due to the inverter technology and heat transfer improvement. But, in the case of start-up, shut-down and intermittent driving, heat pump performance decreases. To improve the efficiency of the heat pump more, we have to grasp the characteristics of these driving in detail. For this purpose, characteristics of the heat pump must be predicted by the simulation globally. In recent study, we suggested the modular analysis as general-purpose thermal system analysis. In this study, we construct unsteady state simulation model of the compression type heat pump and carry out the simulation by using modular analysis. The validity of the simulation model is investigated by experiment using package type air conditioning system whose rated power input is 2.16 kW. As a result, the validity of the simulation model was confirmed by the comparison of simulation results with the experimental ones. For example, experimental data of the pressure were predicted with relative error less than 10%. And it was clarified that the intermittent driving performance of the heat pump is affected by operating method greatly.