During the Spring and Autumn Period, the surface decoration technology for bronzes developed rapidly, with various decoration methods and complex patterns. Color fillers in order to highlight the decorative effects of surface patterns on bronzes are common. However, there are few scientific analyses on the color filler materials for bronzes—the relevant studies are mostly focused on their artistic value and cultural significance. The identification of white fillers is still rare. Zaoshulin Cemetery in Suizhou, Hubei Province is a high-level noble cemetery dating to the Spring and Autumn Period (770 BCE-476 BCE), from which a large number of bronzes have been excavated. In this study, the white filling material in the decorated surface of bronzes from the cemetery was analyzed using FTIR, SEM-EDS, XRD and Py-GC/MS. It was concluded that the main component is a mixture of quartz and an unknown clay mineral. The study provides new evidence for the technique of filling colors on the surface decoration of bronzes in the Eastern Zhou Dynasty (770 BCE-256 BCE). This investigation also serves as a reference for other related research.