The two-phase ejector refrigeration cycle (TPERC) system with a dual-serial-throat nozzle ejector was investigated experimentally, and the entrainment ratio of the ejector and the COP of the system were compared with those of the ejector with Laval nozzle and the TPERC system respectively. The experimental results indicate that the entrainment ratios of the dual-serial-throat nozzle ejectors with different geometric size are greater than those of the Laval nozzle ejectors under the working condition of the evaporating/condensing temperatures 1 ℃/45 ℃, the maximum increment of the entrainment ratio is about 18%; and the COP of the TPERC system with dual-serial-throat nozzle ejector is greater than that of the TPERC system with Laval nozzle ejector, the maximum increment of the COP is about 12%. Under the condition of the fixed evaporating temperature 1 ℃, the entrainment ratios of both the dual-serial-throat nozzle ejector and the Laval nozzle ejector achieve the maximum values as the condensing temperature is about 45 ℃. Under the condition of the fixed condensing temperature 50 ℃, the entrainment ratios of the two types of ejectors achieve the maximum values as the evaporating temperature is about 3 ℃.