In this study, the performance characteristics of a bypass two-circuit refrigeration cycle designed for refrigerators were investigated in a bench scale refrigeration system. The bypass two-circuit refrigeration cycle with R600a operates in two modes of refrigerator/freezer-mode (RF-mode) and freezer only-mode (F only-mode) by switching refrigerant flow path. The performance of the bypass two-circuit refrigeration cycle was measured by varying the condenser capacity, the length of the suction line heat exchanger (SLHX), and the refrigerant charge amount with adoption of the refrigerant storage vessel. The COPs of the bypass two-circuit refrigeration cycle at RF-mode and F only-mode increased by 10% and 17%, respectively, with the increase of the condenser capacity and SLHX length. In addition, the COP of the system at F only-mode increased by 10% with the adoption of the refrigerant storage vessel.