In this course, comparison between traditional Chinese medicine (TCM) and Western medicine is made based on pathology. First of all, the three branches of Western pathology (1) anatomical pathology, (2) chemical pathology, and (3) microbiology will be reviewed; meanwhile, the pathology of TCM based on functions and rhythms will also be discussed. The former is based on the concept of structure, and the latter more of function-oriented. Secondly, we will discuss and evaluate the three branches of western pathology. Thirdly, a few typical cases of disorder and disease will be used for discussion. Fourthly, the pathology of TCM will be proposed and studied under the chaotic wave theory of fractal continuum. To illustrate its effectiveness, the aforementioned disorders will be presented and discussed from the TCM viewpoints. As a result, the pathology of TCM can be better appreciated.