Two A-type granite belts, which are mainly composed of quartz syenites and alkali granites, are distributed along both sides of the Middle-Lower Yangtze Region. In order to study the forming age and tectonic setting of A-type granites in this area, In the present study, LA-ICP-MS zircon U-Pb dating and Hf isotope analyses have been carried out for the quartz syenites from Dalongshan and Huangmeijian in north belt, respectively. The U-Pb data show that the formation ages of the Dalongshan plutons are 125.8Ma±1.6Ma and 126.4Ma±3.5Ma, and the Huangmeijian plutons are 127.6Ma±2.1Ma and 127.2Ma±2.1Ma, respectively. Their corresponding zircon εHf(t) values are -4 to +1.1, -7.8 to -3.6, -3.2 to +2.2 and -3.8 to -0.1 with TDM2 model ages of 1433~1107Ma（average 1264Ma） and 1671~1432Ma（average 1555Ma）, 1387~1043Ma （average 1263Ma）and 1421~1187Ma（average 1310Ma）, respectively. The results indicate that Dalongshan and Huangmeijian plutons are formed in Early Cretaceous, which are contemporary with other plutons of the two A-type granite belts along the Middle-Lower Yangtze Region. The sources of magma likely stem from enriched mantle, which is accompanied by varying degrees of crustal material contamination and fractional crystallization. Based on the present studies, it is implied that the A-type granites from the Middle-Lower Yangtze Region including Dalongshan and Huangmeijian plutons are formed under lithospheric extension and thinning environment, which is related to the Pacific slab roll-back.