With the wide application of the nonlinear power electronic devices and many distributed power connected to grid by the inverters, harmonic distortion has drawn the attention of many researchers. In distortion of power system, it is the premise of harmonic pollution governance to clarify the responsibility of harmonics to be shared between the customer and the power supply system at the point of common coupling (PCC). Firstly, this paper discusses the physical meaning of harmonic responsibility allocation, and the characteristics and existing problems of traditional assessment indices are analyzed briefly. Then, redefines the principle of the harmonic current and harmonic voltage responsibility indices and further proposes new evaluation indices. Finally, combined with the equivalent circuit for harmonic analysis, the overall process of quantitative assessment of harmonic responsibility in practical application is systematically put forward. The rationality of the principle of harmonic responsibility division and the feasibility and effectiveness of the proposed indices of harmonic assessment are verified by the simulation of IEEE14 standard test system.