Abstract: A brief introduction of hypothesis of earthquake and volcano origins by underground avalanche and discharge is made. Based on the fact of existing strong underground discharge and earthquake lighting (such as ultraviolet light, etc.), and the basic fact of organic compounds (such as amino acid, hydrocarbon, oil oligomer, etc.) generated by the process of inorganic matter under the discharge and ultraviolet radiation, the hypothesis of origins of oil, natural gas and diamond by underground discharge or underground radiation is proposed. The positive correlation phenomenon or adjacent phenomena between distributions of earthquake or volcano and the distributions of continental oil and gas fields in China are revealed. It is pointed out that the explorations of oil, natural gas and diamond should pay more attention to the regions where earthquake or volcano has been active and the vicinities where more carbon compounds and groundwater exist underneath.

Key words: oil-gas origin, earthquake, volcano, underground discharge, diamond