A cryogenic refrigeration system is under design by RISP (Rare Isotope Science Project) for a new heavy-ion linear accelerator, RAON, which will be built at Daejeon Korea. RAON will use four types of superconducting cavities which are cooled at 2 K superfluid helium; following IF (In-Flight) separator will utilize HTS and LTS magnets which are cooled at 20-50 K and 4.5 K, respectively. The cryogenic system consists of helium refrigeration system (HRS), helium distribution system (HDS), and cryomodules containing the cavities and magnets. Total capacity of the helium refrigeration system is estimated about 18.6 kW equivalent at 4.5 K. This paper will present current status of the cryogenic refrigeration system for RAON.