Abstract: Laozhaiwan gold deposit, which is currently the largest low-grade fine-granular disseminated type of gold deposits in Yunnan, is located in the junction of Yunnan-Guizhou-Guangxi region. The deposit occurred in altered fine quartz sandstones upon the unconformity of Caledonian ancient uplift. Undergoing the late tectonic activities, magmatism and eluviation, gold in the bearing bed developed gold deposit by the way of migration and enrichment. The development of gold deposit in this area is connected with alteration, such as silicification, ferritization, pyritization. Besides, its formation is also closely related to regional geotectonic development, deep and great rupture developing, magmatism, hydrothermal activity, etc.