By means of thermometry and Raman spectrum technology, this paper has studied c- haracteristics of fluid inclusions of marine lower assemblage in Qianzhong uplift area. The result indicates that the fluid inclusions are characterized by small size， colorlessness and irregular shape, whereas the nature gas is a dry gas mainly composed of CH4. Some CO-bearing inclusions were formed by carbonate ［Ca-(HCO3)2］ decomposition under the condition of temperature and pressure change. The homogenization temperature of inclusions in marine lower assemblage has two temperature ranges, which are 85～125℃ and 125～165℃，respectively. It is thus concluded that the hydrocarbon accumulation periods of this area are Early-Middle Cambrian-Early Triassic and Early Triassic-]Middle-Late Jurassic.