Abstract: Hydrocarbon geochemical exploration (here referring to near-surface geochemical exploration) is a kind of technique for prospecting oil and gas by means of geochemical methods. With the advantage of directness, quickness and cost-effectiveness, this technique has achieved good results in oil and gas exploration practices, and has been widely applied for a certain period. On the other hand, as a new subject, this technique also has some imperfectness in many aspects, in which unreliable stability and frequent repeat of the anomaly are the main obstacles. Based on the geochemical exploration data collected from Biyang sag (Jinglou-Gucheng oilfield) in Henan Province and the southern slope of Linyi sag (Linnan oilfield) in Shandong Province, the authors compared the characteristics of the geochemical exploration anomalies over the existing oil and gas reservoirs of different stages (same years) and different times in this paper, and verified that the geochemical exploration anomaly has favorable stability in the aspects of geochemical indicators combination, structure features, profile illustration and plain distribution of the geochemical anomalies. The results have supported the feasibility of hydrocarbon geochemical exploration technique in oil and gas prospecting, and suggested that this technique will have a bright prospect of wider application in hydrocarbon exploration.