High-temperature heat pumps can be widely utilized for industrial heating as an energysaving method due to their high condensing temperatures. This paper describes a cycle analysis and experimental study on the performance of a high-temperature heat pump (HTHP) system. The performance comparisons are conducted using performance calculations among the parallel cycles with serial heating on the water side, a two-stage compression cycle and a single-stage cycle. The results show that the performance of the heat pump using parallel cycles with serial heating is the best when the condensing