Alternative medicine is defined as the practices used for the prevention and the treatment of diseases that are not taught widely in medical schools, nor generally available inside hospitals. Alternative medicine or therapy is of growing interest to the general public. We conducted a survey to determine the prevalence and patterns of using alternative medicine such as herbal medicine acupuncture, folk medicine, health food and diet, yoga, qi therapy, shiatsu, chiropractics, homeopathy etc.. Based on 794 completed questionnaires, 484 respondents(61%) reported using at least one form of alternative medicine for their medical problems. The major medical conditions for which they used alternative medicine were back pain(85.6%), arthritis(85.4%), hypertension(85.2%), cerebrovascular disorders(86.4%), and insomnia(84.6%). The types of alternative medicine frequently used were herbal medicine, acupuncture, folk medicine, and health food. The reasons why the vast majority of people sought after alternative medicine was that: less side-effect, it is not harmful, it is more effective, there is a shorter waiting time, and a better explanation fur the conditions and a kinder therapist. We found that the frequency of using alternative medicine in the health care system was high. Physicians need to be more aware that many patients may be using alternative medicine. Further survey of the nation-wide prevalence of alternative medicine, and scientific study into the efficacy of this medicine should be followed. In the meantime, we suggest paying attention to possible harmful effects caused by some sorts of alternative medicine.