According to the independent α-cluster model, the reaction cross sections and s pectroscopic factors of the reactions 16O(p,pα)12 C and 16O(α，2α)12C at the energies of 101.5,90 and 140 Me V have bee n calculated by means of distorted wave impulsion approximation. Reaction cross sections and spectroscopic factors calculated are in agreement with experimental data, and are better than the results by using shell model. This indicates that the independent α_cluster model can describe the mechanism of the reactions be tter.