The Fangjiagou site, located in the southeast foot of Songshan Mountain and the east of Dengfeng basin, is an open-air Paleolithic site, and yielded abundant lithic artifacts from the main archaeological layer of the site dated to 50-30 ka BP. Its stone industry is characterized by flake tools. Surrounding area of this site presents a number of rock types of varying availability and quality for knapping, which can help to understand why hominins select specific lithic raw materials during MIS3. Here we report the results of investigation of raw material sources at the Fangjiagou site. We identified the lithology of lithic artifacts unearthed from the Fangjiagou site by hand-specimens, and analysed their prototype according to cortex-bearing pieces. The raw materials can be divided to three groups: Vein quartz blocks are dominant in quantity; Pebble/cobble forms including quartz sandstone, quartzite and vein quartz, also account for a certain proportion; In addition, there is a very small amount of flint, which only appears in the form of chips without cortex. We carried out geological survey within a radius of approximately 15 km of the site to identify potential primary and secondary sources for theses raw materials and compare outcrops with archaeological specimens. First, Middle Pleistocene gravel layer is widely distributed on the top of the hills near the site. According to the analysis of the gravel samples from two exposed sections(less than 1 km straight-line distance from the Fangjiagou site), the hominins mainly chose the rock types with relatively good quality from the gravel layer, and probably procure gravels by collecting ones eroded and peeled from stratum. Second, vein quartz are mostly exposed in the Proterozoic stratum at the southeast foot of Songshan Mountain about 7-11 km northwest of the site. The hominins collected vein quartz blocks around primary source areas and brought them back to make tools. We also investigated other rock outcrops in the study area even if they do not or rarely appear in the Fangjiagou site. In fact, there are potentially available tool-stones with higher knapping quality than vein quartz, such as flint outcrops near the Xishi site, and quartzite as vein quartz country rock. These stones are within the exploitation capacity for MIS3 hominins, but until the blade and microblade technology appeared by 26 ka BP in Dengfeng basin, the main raw material had always been vein quartz. This result challenges the explanations that attributing the lack of formalized lithic technology to raw material constraint factors in China.