Abstract: According to petroleum organic origin theory, the original materials for hydrocarbon generation are the dispersed organicmatters in rocks. But a great amount of actual data indicate that the dispersed organic matters in rocks are not entered into theprocess of hydrocarbon generation, and conditions required for extracting organic matters from powder rock samples in a lab arenot existed in nature. In contrary, there exist inexhaustible free hydrogen and volatile carbonide in deep crust, which may reacteach other under high temperature and high pressure in mantle source,forming hydrocarbon accumulations provided withhydrocarbon fluid such as oil field,gas field,bitumen deposit and combustible shale. They could all be generated by deepinorganic fluid in Neogene.n addition, this paper presents an idea of coal can be formed by deep hydrothermal fluid as thesame as crude oil.During the process of petroleum generation and accumulation caused from mantle hydrothermal fluid,discordogenic fault or transport faulting broken to the mantle would play the most significant part.

Key words: oil and gas origin, coal, organic origin, inorganic origin, mantle, hydrothermalism