As there is lack of effective division for liability of harmonic pollutions caused by non-linear loads and there is no accurate localization of harmonic sources in complex distribution network, the method based on information entropy for localization of multiple harmonic sources is proposed. All the harmonic data measured is gained by harmonic separation using support vector machine and then probability density is estimated by using the B-spline method, thus, the value of mutual information regarding bus bar voltage and current of each branch can be figured out and the position of main harmonic sources can be confirmed according to the value of mutual information. Through simulation analysis of typical power distribution system in alternative transient process (ATP) software, the result shows that the method proposed has the advantage of accurate location and is able to divide the real liability of harmonic pollutions.