Checking the consistency of knowledge items between textbook and clinical practice is very important for traditional Chinese medicine (TCM). According to the textbook of internal medicine of TCM, rheumatoid arthritis (RA) is a disease with four syndromes (also called pattern) and Feng-Han-Shi-Bi is the major one. Bisimulation is an equivalence relationship/method in formal methods which can be used to compare the consistency of system's description and its behaviors. In TCM, knowledge items from textbook can be taken as system's description, and knowledge items from clinical practice can be taken as the behaviors of the system. For RA's Feng-Han-Shi- Bi syndrome, employing bisimulation method, the consistency of knowledge items between textbook and clinical practice has been checked. As a result, on Feng-Han-Shi-Bi syndrome, most knowledge items in textbook can be simulated by the clinical practice while two others cannot be simulated e.g., Han-Re- Cuo-Za syndrome in clinical practice and Fang-Feng-Tang in textbook have no exact bisimulation items. In brief, bisimulation is a proper method for consistency check between TCM textbook and clinical practice.