Abstract: The analyses of fluid inclusion characteristics of reservoirs in the Kelasu tectonic zone of the Kuqa Depression show that saline inclusions are abundant while a few of gaseous hydrocarbon inclusions and gaseous-liquid inclusions also exist. The inclusions mainly locate in quartz as lines or in planar distribution. They are small, usually about 4-10 μm. The homogenization temperature of saline inclusions is 86.2-196.1 ℃, usually in continuous distribution and varies between different regions. The salinity of saline inclusions is low, generally 2%-4%. The hydrocarbon inclusions have low abundance, usually 0.1%-8.1%. It has been concluded that natural gas charged rapidly and continuously in the Kelasu tectonic zone, and the late charging had stronger strength. Burial history studies show that natural gas accumulations have occurred ever since the Kuqa period, and are later in the Keshen zone than in the Kela zone. From east to west, accumulation period becomes later and later.