Using trace element concentrations of consanguineous primary magmas formed by different degrees of equilibrium partial melting, the author has put forward an inverse method for quantitatively calculating trace element abundances of source rocks. In the inverse calculation, there is no need to assume parameters such as C0, D and F, so it provides an effective means for studying geochemical composition of the provenance.In addition, the paper has dealt with the genesis of the Cenozoic olivine tholeiites and alkali basalts and the characteristics of the upper mantle in Hannuoba area. The inverse results show that the upper mantle had obviously undergone enrichment of REE relative to chondrite before the melting process, with different rare earth elements experiencing obviously different degrees of enrichment.