Abstract As a natural refrigerant, HC290 is considered as an excellent long-term alternative refrigerant applied in room air-conditioners (RAC). In this paper, the experimental study on tribological characteristics of the vane–roller friction pair in HC290 rotary compressors was carried out and friction coefficients and wear depths were measured under the pure HC290 atmosphere, pure mineral oil and HC290/mineral oil mixture environment, respectively. In order to obtain the experimental conditions as close as possible to the actual operating conditions of a HC290 rotary compressor, the mass-produced vanes and rollers were adopted, and all tests were performed with a high-pressure tribometer under various sliding speeds, loads and temperatures which were set to simulate the different actual operating conditions of rotary compressors. Furthermore, the scuffing tests were performed and the Scanning Electron Microscopic has been used to investigate morphological changes occurred after test. The experiment results with the HC290/mineral oil mixture showed that better anti-scuffing ability but a higher friction coefficient of vane–roller interface were acquired compared to HFC410A/polyolester. The results obtained here may provide some guides for further investigations on tribological characteristics of the vane–roller interface of HC290 rotary compressors.