As the boundary of water source energy has recently expanded to the use of river, lake, and pond waters, the water source heat pump (WSHP) system is becoming a major issue. However, to apply the WSHP system to a real building, a comparison and analysis with a ground source heat pump (GSHP) and an air source heat pump system (ASHP) are required. Moreover, it is necessary to accurately analyze the performance of a WSHP based on the building load condition. Therefore, this study aims to analyze the performance of WSHP, GSHP, and ASHP systems for large office buildings using a dynamic energy simulation. The seasonal performance factor (SPF) of the system was calculated as 3.8 and 2.5 for a WSHP system, 3.8 and 2.6 for a GSHP system, and 2.9 and 1.7 for an ASHP system during the cooling and heating periods, respectively. The performance of the WSHP system was similar to that of the GSHP system and was 23% and 32% higher than that of the ASHP system, respectively.