Abstract: The depositional system for hydrocarbon source rocks of Jurassic in Fukang sag is a set of swamp---shallow lacustrine coal-bearing deposits. The systematic analysis of hydrocarbon-generating potential indicates the mudstone is of high organic matter abundance, the main types of which are Ⅱ2-Ⅲ and in medium heat evolutionary stage. The previous study showed that the source rock from Jurassic accounted for 60% averagely and had a significant role in hydrocarbon exploration process in Zhundong area.