Objective To establish case database of critical illness and explore the effect of critical case-based learning in the anesthesiateaching program as well as its influence on clinical thinkingability of students. Methods Case database of critical illness was built with foxtable software and ASAⅢ~Ⅴpatients undergoing anesthesia were included in the case database. Patients' information were recorded according to the sequence of pre-operative evaluation,intra-operative management and post-operative recovery. We designed a studentquestionnaire to investigate the effect of critical case-based learning. And we also compared the effect of critical case-based learning and traditional teaching on undergraduate interns, residents, and graduate students by scores of case analysis test. Data analysis used t test. Results The critical cases database is characterized by authenticity, hierarchy and for-wardness. Survey result of questionnaire shows that the proportions of studentswho believe critical case-based learning helps to strengthen the links of theory and clinical practice, to improve expression skills, and to promote active classroom atmosphere, solidarity and cooperation are 80%, 71.6% and 68.3%respectively. Compared with those who received traditional teaching, the residents and graduate studentswho received critical case-based learning get significantly higher scores in case analysis test. However, the difference of scores between undergraduate interns receiving traditional teaching or criti-cal case-based learning has no significance. Conclusion The establishment of critical cases database and its application in anesthesiateaching program have effectively improved clinical thinkingability of anesthesia residents and graduate students.