Based on the observations of thin sections and cores from 60 wells; five types of dolostone reservoirs can be recognized from the Cambrian-Ordovician carbonate rocks in Tarim basin. Sabkha dolostone reservoirs developed in intertidal to supratidal flat environment with gypsum-dissolved porespace and collapsed interbreccia porespace scattered in fine dolostone. Seepage reflux dolostone reservoirs that are characterized by fabric selective dolomitization developed in evaporite lagoon environment with moldic, gypsum-dissolved and intergrain porespace. Subsurface dolostone reservoirs that are characterized by replacement of limestone and recrystallization of fine dolomite developed in burial environment with intercrystalline porespace. The development of hydrothermal dolostone reservoirs that are characterized of coarse dolomite and accompanying hydrothermal mineral are controlled by faults and unconformity. Fractures are common in dolostone which is composed of fractured dolostone reservoirs. Different types of dolostone reservoirs have their own different origin and distribution.