Abstract: The dolomite serves as the most important reservoir which has always been the key to the evaluation and exploration of oil and gas. The oil-bearing dolomite was found recently near the Dazhuoma area, Amdo. The oil-bearing dolomite develops in the Buqu Formation of Middle Jurassic with the thickness over 30m and the length over 80m. The rocks are the medium-coarse-grain dolomite. The porosity of the samples is in the range of 5%~17% and the permeability is from 2.84×10^-3μm² to 236×10^-3μm². The dolomite belongs to the low-porosity and low-permeability to medium-porosity and low-permeability reservoir which is similar to the high quality dolomite of Longeni. The new oil-bearing dolomite found in Amdo lies in the same layer as the dolomite in the Bi-luo Co-Angdaer Co zone, from which the authors infer that the oil-bearing dolomite has an east-west distribution for about 180km and is the most important reservoir in the basin. The discovery of oil-bearing dolomite in Dazhuoma area expands the distribution and extent of dolomite reservoir, which can provide new basis for the oil exploration and disposition in Qiangtang Basin.