This paper determined a P-wave velocity structure of upper mantle beneath the southeastern part of South China, with the emphasis placed on the Qinhang Joint Belt, by using 121 teleseismic events received by 114 permanent seismic stations. The results show that:(1) the deep structures of the Qinhang Joint Belt, the Wuyi Metallogenic Belt and the Nanling Metallogenic Belt are different, suggesting that the tectonic processes of the three metallogenic belts are also different; (2) there exists a low velocity anomaly in the upper mantle beneath the Jiangshao Fault, suggesting that the upwelling of thermal flow probably originated from mantle transition zone or lower mantle, and might have been closely related to the mineralization in the Qinhang Joint Belt and the Wuyi Metallogenic Belt; (3) the high velocity anomaly at the bottom of the upper mantle beneath the Yangtze Block is probably the detached lithosphere; however, the high velocity anomaly beneath the Cathaysia Block should be further studied. These results provide new evidence for understanding deep structure about the southeastern part South China.