Abstract: The conventional harmonic responsibility determination method needs the specialized equipment to measure harmonic voltages and currents of users synchronously, therefore its engineering applications are limited. In this paper, a method for the responsibility determination of multiple harmonic sources based on interval-type monitoring data, which is the asynchronous measurement data from harmonic monitoring devices, is proposed. First, interval monitoring samples are constructed from the existing harmonic monitoring data. Then, the scenarios are divided by the linear dynamic clustering algorithm based on the parameterized method to ensure that the harmonic impedance variation and the background harmonic voltage fluctuation are kept in a small range in each scenario. Subsequently, the interval linear equations for quantification of harmonic responsibility are established and the interval parameters are identified by the correlation data selection method. Finally, a harmonic responsibility interval index is proposed to evaluate the harmonic responsibility of harmonic sources quantitatively. The feasibility and effectiveness of the proposed method are verified by simulation and arithmetic cases.