Abstract: In order to discriminate normal and abnormal heart sounds (HSs) accurately and effectively, heart sound characteristic waveform (HSCW) method is proposed to analyze HSs. Characteristic waveform is extracted from an analytical model of single degree-of-freedom (SDOF). Furthermore, characteristic parameters are calculated to discriminate normal and abnormal heart sounds. A case study on abnormal HSs from a heart patient before and after surgery demonstrates the validation of the usefulness and efficiency of the proposed HSCW method. Besides, 50 normal and 30 abnormal HSs are collected and analyzed, the accuracy performances are achieved by 98% and 93.33% respectively.