To relieve soil thermal accumulation and performance degradation over a long-time operation for ground source heat pump (GSHP) system in cooling-dominated area, a hybrid GSHP system with cooling tower (HGSHP) was proposed. The purpose of this paper is to study the performance and feasibility of HGSHP in Shanghai. Firstly, the simulation model of GSHP system for an office building was established by TRNSYS 17.0 and the reliability of simulation was validated by the measurement data. Then, one-year and ten-year variation of performance parameters of GSHP and HGSHP systems were calculated respectively and explored in depth. These results shown that, compared with GSHP system, the annual average electricity consumption of HGSHP system decreased by 6.40% and coefficient of performance (COP) increased by 7.12% during the first year of operation. Additionally, the outlet temperature of buried pipes was below 32 degrees C for HGSHP system during ten-year operation, while in GSHP system, the over standard rate of outlet temperature of buried pipes could reach approximately 80% and soil temperature increased by 10.9 degrees C. These findings indicated that HGSHP system could provide a feasible solution for cooling and heating in hot summer and cold winter zones. (C) 2019 Elsevier Ltd. All rights reserved.