Abstract: The Lower Paleozoic dolomite is widely distributed in Tarim Basin with a large thickness and good conditions for source-reservoircap assemblage. It is the important exploration field in the basin. Great exploration efforts have been focused on Lower Paleozoic dolomite since Tarim Basin was brought under exploration and development, but no significant discoveries have been made in this field. Based on a better understanding of the stable reservoir-cap assemblage and the accumulation conditions for palaeohigh, the exploration mindset was changed around 2010, being concentrated on the Tazhong successive palaeohigh. With application of 3D seismic assessment technology, Zhongshen-1 Well was drilled, which made a breakthrough in Cambrian subsalt dolomite and turned a new page of Cambrian dolomite exploration. Two sets of oil and gas horizons of the Middle-Lower Cambrian series were found at Zhongshen-1 Well. One set is located in Awatage Formation of the Middle Cambrian series in the form of low-density wax-containing light crude oil, while another set is located in Xiaoerbulake Formation of the Lower Cambrian series in the form of dry gas reservoir. The breakthrough of Zhongshen-1 Well is of great significance to oil and gas exploration of Tarim Basin. It is the first time to find inner-curtain dolomite hydrocarbon reservoirs in the basin, confirming the petroleum geological conditions for large-scale hydrocarbon accumulations in Cambrian subsalt dolomite and locating a new strategic replacing field which has an extensive area of nearly 30×10⁴km². Meanwhile, discovery of Cambrian subsalt hydrocarbon reservoirs at Zhongshen-1 Well indicates that Cambrian source rock is likely to be the main hydrocarbon source rock in the platform-basin area of Tarim Basin. This discovery exerts a far-reaching influence on exploration of the platform-basin area of the basin.