In order to explore the differences in raw material selection and processing techniques used for pottery-making during the Western and the Eastern Zhou Dynasties at Guanzhuang site, Xingyang, Henan Province, we studied the materials and blanks of sandy and clay pottery, Holocene paleo-soil, Malan loess, and river sands from Ku River near the site. Samples were analyzed using a particle size analyzer, a magnetic susceptibility meter and an X-ray fluorescence (XRF) spectrometer. The results show that 1) earthenware clay of Guanzhuang pottery came from the sedimentary strata dating to the late Pleistocene and Holocene, where Guanzhuang site is located; admixture of the sandy pottery clay and blanks are mainly river sands taken from the channel of Ku River; 2) during the use of the site, techniques for the selection and processing of pottery clay differed from the early to the late periods. In early days, clay from Malan loess or Holocene paleo-soil was elutriated (1~11 μm) and then mixed with river sands to make sandy pottery. The proportion of coarse-grained river sand to fine-grained clay is 1∶4; in the later period, Holocene paleo-soil was used as the earthenware clay, and was prepared directly or only after a simple elutriation process.