Mineralogical characteristics and ink-making mechanism of Hongsi inkstones from Linqu in Shandong Province were studied by means of petrographic observation, X-ray powder diffraction (XRD), and microhardness testing. By imitating the artificial ink-grinding, the authors designed an experiment to compare the difference between ink-makings, and quantitatively evaluated the advantages and disadvantages of the ink-making of inkstones by using slice observation creatively. The results show that quartz is the main functional mineral of the inkstones for ink-making, whereas the primary factor which influences the ink-making of the inkstones is the difference of quartz content and texture, such as roundness and grain size