Gem-quality garnets in Jinan of Shandong Province occur on the northern margin of the middle basic rock mass in the urban area. Because of badly ruined profiles and lack of gemological reference, gemological instrument, FTIR, EPMA and UV-VIS were used to investigate the characteristics of Jinan garnets. Jinan garnet's host rocks can be divided into early-formed skarn and late-formed pegmatite. Skarn garnet crystals are subhedral to unhedral in form, and their main component is andradite with minor grossular, mainly black-palm red or orange red and minor green in color. The pegmatite garnet's crystals are mainly of euhedral rhombic dodecahedron shape, mainly in green or yellow color, and the component is mainly grossular with minor andradite. Inclusions of pegmatite garnets are mainly needle-like actinolite and feldspar crystal inclusions. Jinan garnet crystals can show obvious bands of black-reddish brown-yellow-yellowish green-green color from the early epoch to the late. Green garnets have the characteristics of abnormal extinction, uneven Cr content, high Fe-Ti-Cr content in dark green rims and low content of Y. Black garnets have high Ti content and contain black spinel inclusions. The spinel and actinolite inclusions in Jinan garnets are different from gem-quality garnets of other regions.