Nanpu depression is one of the main oil-producing region in Huanghua depression, oil and gas reservoirs in this depression must be of favorable reservoir forming conditions. This paper applies reservoir anatomy, geochemical data analysis, fault activity periods, source rock hydrocarbon expulsion period, caprock identification and sand and stratum ratio analysis and other measures, uses the reservoir conditions of comprehensive analysis method to study in detail and analyze the source rock, caprock, fracture, reservoir and structural position in 5 aspects in terms of geological condition, we clearly determined hydrocarbon accumulation conditions and their relationship in Nanpu depression. It is considered that there are five favorable geological conditions for oil and gas accumulation in Nanpu depression: ① two source rocks whose thickness is high and the distribution is wide so as to provide adequate oil and gas for migration and accumulation; ②two source rocks provide transporting pathways for oil and gas to migrate; ③three regional caprocks provide sealing for oil and gas to accumulate; ④strata with high ratio between sand stone and stratum so as to provide reservoir space for oil and gas to accumulate; ⑤positive structures near faults connected source rock so as to provide favorable places for oil and gas to accumulate. Through the study of this paper, it will be enriched hydrocarbon accumulation in Nanpu depression, and provides a new thought for next exploration of oil and gas. The result of this study offers important significance to guide the oil-gas exploration in depression basin.