Lying at the junction of the Yangtze paleoplate and the Cathaysian paleoplate, Guangfeng and Yushan basins are characterized by red clastic rocks and mafic volcanic rocks. SHRIMP U-Pb dating of zircon shows that shoshonite in Guangfeng and Yushan basins has an age of 93±1 Ma, belonging to early Late Cretaceous. (⁸⁷Sr/⁸⁶Sr)_i values of shoshonite in Guangfeng are 0.706 191～0.706 352, εNd(t)=0.27～0.55, (²⁰⁶Pb/²⁰⁴Pb)_i=18.045～18.08, (²⁰⁷Pb/²⁰⁴Pb)_i=15.503～15.543, and (²⁰⁸Pb/²⁰⁴Pb)_i=38.240～38.256, whereas (⁸⁷Sr/⁸⁶Sr)_i values of shoshonite in Yushan basin are in the range of 0.705 856～0.706 024, εNd(t)=1.74～1.93, (²⁰⁶Pb/²⁰⁴Pb)_i=17.956～18.063, (²⁰⁷Pb/²⁰⁴Pb)_i=15.456～15.498, and (²⁰⁸Pb/²⁰⁴Pb)_i=38.195～38.232. In the (⁸⁷Sr/⁸⁶Sr)_i-(²⁰⁶Pb/²⁰⁴Pb)_i, (¹⁴³Nd/¹⁴⁴Nd)_i-(²⁰⁶Pb/²⁰⁴Pb)_i and (¹⁴³Nd/¹⁴⁴Nd)_i-(⁸⁷Sr/⁸⁶Sr)_i diagrams, the values fall exclusively between the DMM and EMⅡpositions, (⁸⁷Sr/⁸⁶Sr)_i and (²⁰⁶Pb/²⁰⁴Pb)_i show positive correlation, whereas (¹⁴³Nd/¹⁴⁴Nd)_i and (²⁰⁶Pb/²⁰⁴Pb)_i show negative correlation, which suggests that the source mantle of the shoshonite rocks probably had both DMM and EMⅡ magma, with a higher proportion of DMM in the Yushan basin.