Abstract: Over 180 super pressured basins in the world have been found today, of which more than 160 are rich in hydrocarbons. The oil-gas fields with abnormal high pressure account for about 30 percent of the total fields. Compared with the normal pressure condition, the abnormal high pressure source rock tends to having lower gas production rate and organic matter maturity, but higher oil production rate, in the same conditions. The incremental pressure may postpone and restrain the organic matter maturity and hydrocarbon generation. The relationship between the pressure and the maturity in the abnormal high pressure system is analyzed. The effect of the abnormal high pressure on the hydrocarbon generation is discussed with some cases. Also, the types, origins of abnormal high pressure as well as their guiding roles to future

Key words: abnormal pressure, origin, hydrocarbon generation, thermal maturity, thermal evolution hydrocarbon exploration are presented in detail.