In order to clarify the problem of oil-gas source, and by means of the total hydrocarbon chromatography analysis and thermal evaporation hydrocarbon chromatography analysis of crude oils and oil sands, we discover that, there are similar light hydrocarbon geochemical characteristics between northern heavy oil and southern light oil. Its original organic matters are all sapropelic and the crude oils are all mature reflected by light hydrocarbon. Taking account of the fact that the light hydrocarbon characteristics of different type oil are similar, it is concluded that the light weight fractions of early charged oils are dissipated or degraded, and the light weight fractions of present heavy and light oil are mainly from the late charged oils, so the present oils show the characteristic of late charged oils.The source rocks of late charged oil in this area are rich in lower hydrobios. Based on the correlation of source rocks in Junggar Basin,it is concluded that, the late charged crude oil is derived from Permian source rocks of Changji sag.