Patients received coronary artery bypass graft (CABG) were selected as examples to describe the changes during the implementation of clinical pathway in a medical center around the northern part of Taiwan. A total of20 cases was selected during the three periods of before implementation, the early stage of implementation, and 2 years later. The results indicated that length of stay (LOS) after 2 years was 17.95 days where was the LOS is 13.7 days in the early stage of implementation. Variances such as: patient's variance; practitioner variance; system variance; and community variance had been improved. The medical staff should simplify the medical and nursing interventions as ways of improving the efficiency of clinical pathway. Then, adequate quality of care, shorter length of stay, and cost saving can be achieved.