The Yantizishan deposit situated in the south part of the Moshishan was formerly referred to as an iron deposit. Based on update investigation and exploration in recent years, the authors believe that it is actually a large metamorphosed sedimentary anatase-dominated deposit belonging to a new genetic type. Simultaneously, the Moshishan ore belt was discovered. Ore bodies occur in stratoid and lenticular forms in Mesoproterozoic (1751 Ma) schist, metasandstone (metasiltstone), and amphibolite. Rich ores have perthitic structure comprising chiefly interbedded quartz perthite and anatase perthite. Ore minerals are mainly anatase and subordinately rutile and ilmenite (±hematite), while nonmetallic minerals are chiefly quartz with a certain amount of anthophyllite and biotite (±garnet). The grain sizes of anatase, rutile and ilmenite are 0.01~0.1 mm. Rich ores contain 3.14% to 15.46% TiO2 ,averaging 6.91%, while the low-grade ores have TiO2 content about 1.2% to 2.97%, averaging 1.76%. The ores have relatively high Fe and V contents. According to their relatively low Nb and Cr contents in anatase and rutile, source anatase and rutile must have come from meta-mafic rocks. The protoliths of amphibolite wall rocks should be basalt and picrite-basalt. Pertochemical data suggest that the tectonic setting of these rocks belongs to an island arc or a transitional belt between the island arc and oceanic ridge. Silicon isotope study shows that δ30Si values of different anatase ores, quartzite, and schist in this deposit are 0.1‰ to -0.9‰, similar to those of marine hydrothermal exhalative sedimentary deposits. All of these geological and geochemical characteristics of the ore deposit suggest that the anatase ores and amphibolite are products of submarine basic volcanism. The ores had chemical precipitation features, but were later subjected to regional intermediate (or somewhat lower) grade metamorphism. Rutile was formed mainly in the process of this metamorphism. The ore belt locally underwent hydrothermal modification during the emplacement of Late Yanshanian granite (118 Ma).