East Gobi molybdenum deposit in Xinjiang is the first superlarge molybdenum deposit discovered in the northwest China.Genetically it is a porphyry molybdenum deposit.The host porphyry is absolutely concealed.The article stresses the geochemical anomaly characteristics and the geochemical anomaly characteristics-based prospecting thinking.Relation of F,B anomaly to magmatic hydrothermal fluid was used to judge the concealed porphyry to depth and make a breakthrough in the molybdenum ore exploration.