Abstract: In just a few years after the beginning of 21th century, the arguments against the organic origin theory have been kept going.The studies of inorganic petroleum origin abroad (e.g.America, Russia, etc.) have been made in progress.The in-depth analyses of some fundamental issues in petroleum geology about origins of gypsum-salt, dolomite and clay mineral, etc.have been conducted.The relationship among deep fluids, mantle plume and hydrocarbons is beginning to arouse more attentions.The more important thing is that the inorganic petroleum origin theory has been applied to the practices for oil-gas exploration at home and abroad for prediction of targets of hydrocarbon prospecting to come.It is concluded that the modern concept of inorganic petroleum origin has gradually been formed.

Key words: petroleum origin, inorganic origin theory, prospecting practice, target prediction