A prototype of a Multifunctional Solar Assisted Heat Pump (MSAHP) system is designed in the study. The system integrates a heat pump water heater, a conventional air-conditioning unit and a solar water heater, and takes advantage of their multiple functions in terms of solar and heat pump water heating, space cooling only, space cooling integrated water heating, and air-source/water-source heat pump space heating. The principle and different operating modes of the system are presented. The experimental study of the prototype of the MSAHP in the space cooling integrated water heating mode was conducted. The results indicate that the combined energy efficiency ratio (EERc) of the system fluctuated between 3.39 and 6.20 in this mode. Experiment was also conducted to test the relevant performance functions of the system in the space cooling only mode. The results show that the energy efficiency ratio (EER) of space cooling only mode is 2.61.