The application fields of Compton scattering have been further broadened through the studies of theories and experiments as well as the electronic structure of the scatters. The relationship between the contents of binary alloys (also binary powder mixtures) and the number of Compton scattered photons has been thoroughly examined. The linear expression of the relationship has been obtained approximately according to the Compton scattering theory. And the relationship has been validated well through the Compton scattering experiments with the scatters of Cu-Ni binary alloys or Cu-Ni binary powder mixtures. Furthermore, it is found that the slope of Cu-Ni powder mixture series is steeper than that of Cu-Ni alloy series, and through the pseudo-potential plane wave theory of DFT the microscopic principles of Compton scattering of Cu-Ni alloy and Cu-Ni powder mixture series have been discussed and compared with each other. The results show that the electronic structure is the main reason for the difference of the linear slopes, and the line slope of Cu-Ni powder mixtures series is steeper than that of Cu-Ni alloy series.