Abstract: In order to evaluate the performance of a relay system, propagation characteristics of relay channels are necessary, especially in urban micro-cell (UMi) environment. We conducted wideband relay channel measurements at 2.35 GHz in two UMi sites in China by employing a real-time channel sounder. Three types of links-base station to mobile station (BS-MS), relay station to mobile station (RS-MS), and base station to relay station (BS-RS)-were measured separately at three sites. Statistical propagation characteristics are presented and compared in this letter, including path loss (PL), root mean square (rms) delay spread (DS), and angular spread (AS). These results are informative for the technical research and evaluation of the relay system.