Based on some traditional oil and gas geochemical exploration methods such as acid-extraction hydrocarbon, alteration carbonate, fluorescence spectrum and ultra-violet spectrum, some new methods (indicators) have been established including heat-released hydrocarbons, aromatic hydrocarbons from high-performance liquid chromatography, physically-adsorbed hydrocarbon gas, and obligate hydrocarbon-oxidizing bacteria. New application areas of the hydrocarbon geochemical exploration technique have been developed in the non-conventional oil and gas resources such as gashydrate and non-organic gas, under the complex geo-morphological conditions such as the desert, the gobi area, the loess covered area, and the mountain area, etc., and especially in the offshore environment such as the South China Sea, the East China Sea, the Yellow Sea, the Bohai Sea and the Taiwan Strait.