According to the method of alternative materials compatibility study accepted by an international institute, an experimental device to study the compatibility between refrigerant and materials was designed and constructed. The compatibility between ethyl fluoride (HFC-161, C2H5F, CAS No. 353-36-6) with/without the presence of lubricant oils (polyolester (POE) and polyalkylene glycol (PAG)) and five types of plastics (acrylonitrile butadiene styrene (ABS) plastic, polytetrafluoroethylene (PTFE), polypropylene (PP), polyvinyl chloride (PVC), and nylon) and three types of elastomers (natural rubber, silicone rubber, and neoprene) was evaluated in the high-pressure glass tank at 60 degrees C, respectively. The experimental results indicated that PTFE, PP, PVC, and nylon, as well as silicone rubber and natural rubber, could be used in the refrigeration systems of HFC-161, while ABS and neoprene were not recommended. The absorption of POE oil by the three types of elastomers was stronger than that of PAG oil. Furthermore, results showed that the presence of the lubricant oils could reduce the corrosive effect of HFC-161 to ABS to some extent.