Abstract: The deep origin of ore-forming is a new theory for prospcting in-situ leachable sandstone type uranium.Tectonics,lithology and geochemistry are the basic forecasting criteria.Previous unconsolidated sand, source area and geochemical barrier are three essential conditions for the forming of uranium deposits.Favorable metallogenic enviroment and potential region have been found.The Tertiary system is a promising layer for prospecting in-situ leachable sandstone type uranium in the south of Song Liao Basin.