Abstract: Hydrothermal deposits are usually distributed in association with oil and gas fields. In the China's crude, there are many mineralized elements whose content are twice of the average content of the China's continental crust, with 38 in Xinjiang crude (accounting for 64.41% of the elements detected),35 in Liaohe oil (accounting for 77.77%), 35 in Daqing oil (accounting for 58.33%),16 in Dagang oil(accounting for 28.07%) respectively. This is caused energy carried in mineralized thermal liquid over 3509C and the mineralized elements from the deep portion of the earth. When mineralized thermal liquid and the organic matter meet and react with each Other,the temperature Prompted transformation of organic matter into hydrocarbon matters while the mineralized elements enhanced combination of more carbon atoms and hydrogen atoms in the Organic matter, and accelerated the process of transformation from organic matter to hydrocarbons and enhanced transformation. The hydrocarbon compounds generated by catalysis of mineralized thermal liquids are rich in mineralized elements,which resulted in the fact that the hydrothermal deposits are adjacently distributed with oil and gas fields.

Key words: hydrothermal deposit, oil and gas field, mineralization, element analysis, crude oil