Surface properties of several ink-jet papers were measured, and coating layer structure properties (including pore size, pore size distribution, pigment particle size and shape, etc.) was analyzed through Scanning Electron Microscope (SEM). A testing image composed of a series of lines and dots was designed and got printing image on four ink-jet papers by Epson printer. The printing dot and line quality, which could reflect the sharpness of image, were measured by image analytical method with QEA Image Analyzer. Dot quality (diameter and circularity) is influenced by paper coating structure, ink absorption and contact angle. With the increasing of the printing resolution, the line quality (width and edge roughness) is less influenced by paper properties. For all ink-jet papers, 2#paper (De Ying RC) and 3#paper (Epson half glossy EP313) has better printing sharpness.