///By systemic study the alluvial-proluvial fan of Bauxite series, Jiujialu formation in middle Guizhou Province, it thought that this sediment is the continental deposit accumulated by the alluvial-proluvial process and lake process in the negative relief. The alluvial-proluvial fan is a normal kind of sediment of the alluvial-proluvial facies. Most of the big scale alumina deposit in the central Guizhou formed of the scalloped and sheetlike.