Abstract:No.121 vein in Dayuan mine area in Longkou of Shandong province occurred in north of Linglong gold deposit in Jiaoxibei. Ore bodies directly occurred in Linglong granite body, and controlled by torsional fracture structures with the trend of NEE. The ore types are mainly beresitized cataclasite accompanying with quartz vein, and the genesis type is medium and low temperature hydrothermal quartz veins. Through study on Linglong gold field, from the aspects of strata, magmatic rocks and orecontrolling characteristics, characteristics of ore bodies and the genesis of the deposit have been analyzed, and the metallogenic regularity has been summarized. Linglong brush structure controlled the distribution of gold deposits in the area, and the ore bodies are controlled by the faults with the trend of NEE. Beresitization cataclastic rock with quartz vein is the direct sign of prospecting. Through comprehensive study, there are some prospecting space in No.121 vein, and there is also favorable for the following ore area in the deep part of -400m. It will provide geological basis for next exploration in the future.