Plate heat exchangers and terminal heat radiators usually take a major initial capital investment in a low-temperature geothermal heating project. in this article, a method of arriving at an optimum design of the plate hear exchanger and the corresponding terminal hear radiators in a geothermal heating system is proposed. A comparison is made between the results of the optimized design and those by the conventional design, The effects of the configuration and some parameters of plate heat exchangers on the design results are discussed. Emphasis is also given to how to obtain the best operation status while a geothermal well is producing at constant flow rate and wellhead temperature.