Majiayuan Cemetery is located in Zhangjiachuan Hui Autonomous County, Gansu Province. Many types of beads have been excavated from Tomb M4 of the cemetery. In this work, one of the beads was chosen as a sample in order to study its glaze, which was completely detached from the body part. Scanning electron microscopy with energy dispersive spectrometry (SEM-EDS) and micro-Raman spectrometry were applied to the analyses of microstructure and composition. The results show that the sample is a faience bead with a highly vitrified glaze. Because of corrosion, the flux in the glaze was below the detection limit. The application glazing method or cementation glazing method might be used for this bead. The crystal particles in the glaze were identified as tin dioxide (SnO₂), indicating that tin powder might have been added deliberately. The results also reveal another additive of tin (Sn) instead of lead (Pb) as the flux in faience glaze-making during the Warring States Period of ancient China.