Abstract: Since the 13th Five-Year Plan, in accordance with the guiding ideology of “marching toward unconventional oil and gas and prospecting oil and gas in deep strata”, the Qinghai oilfield has vigorously promoted the exploration of unconventional and deep oil and gas resources and the studies on related theories. Over several years of research, a series of new progresses and new understandings have been achieved：the hydrocarbon-generating parent material in saline-lacustrine source rocks and its hydrocarbon generation mechanism have been identified; a hydrocarbon generation model including interactions among soluble organic matter, kerogen and minerals has been established, which is so called “three-factor controlling” hydrocarbon-generation model; the characteristics and forming mechanisms of fine-grained carbonate reservoirs, deep clastic reservoirs and basement reservoirs have been summarized; and the hydrocarbon accumulation patterns of mixed carbonate reservoirs and deep clastic reservoirs have been built. Guided by these theoretical understandings, a series of exploration targets such as the deep mixed carbonate reservoirs in the Yingxiongling structural belt, deep clastic gas reservoirs in the north Lenghu slope, and basement gas reservoirs in the piedmont of Altyn Tagh mountain have been proved and significant discoveries have been gained. As of April 2019, the cumulative incremental proved OOIP is 2.5×108 tons of equivalent crude oil