Bishop and Paling mining areas in Postmasburg district are taken as the target of research, and six lithological units are identified for the stratum, which are dolostone unit, iron-manganese ore unit, ferruginous fine sandstone/ferruginous conglomerate unit, politic siltstone unit, quartz/Gamagara shale unit and Paling shale unit. Three types of ores, sedimentary-metamorphism, cumulate type, and manganese mud or wad type, are identified and the genetic models are discussed. According to the depositional sequence, the development and evolution process of the study area is divided into four stages. The result shows that manganese mud or wad is the residues of the manganese rich dolostone after corrosion. The units in the depositional sequence have a gradual transition relationship while the depositional sequence is unconformable with dolostone. All of the three types of ores are related to the karst system, and Mn in the manganese mud or wad origins from manganese rich dolostone, while in the other two types probably origins from andesite. The sedimentary-metamorphism type and cumulate type of ores are formed after karst system respectively. The orebodies are preserved with the protection of Marthaspoort quartz after metallogenesis.