<p><i>Gui</i> is a typical pottery type during the Neolithic Age in China and the structure of <i>Gui</i> has been considered to be convenient for boiling. The symbolic significance of <i>Gui</i> in ritual activities has been emphasised. However, its uses associated with food processing are unclear. Calcified deposits have been observed on the inner surface of pottery <i>Gui</i> and some were suspected as water scales formed during the boiling of water. In this study, multi-analytical approaches including scanning electron microscope, X-ray fluorescence, X-ray diffraction, infrared spectrometry, Raman spectrometry, carbon and oxygen isotope, lipid and protein analysis were conducted to reveal the compositions of calcified deposits on the pottery <i>Gui</i> and other vessels at the end Neolithic site of Tonglin in China. The analytical results showed that the calcified deposits are composed of two crystal structures of calcium carbonate, calcite and aragonite. Plant residues including plant oils, millet and fruit lipid biomarkers, were detected in the water scale deposits, as well as animal bone remains, indicating the diversified uses of <i>Gui</i> for food processing. The multiple functions of <i>Gui</i> may facilitate the formation of its ritual symbolic significance in China.</p>