Avian Influenza (AI) has made hundreds of people dead in Europe. The hospital system of Taiwan, standing in the first line of prevention and treatment, has to effectively employ the experience of SARS in order to tackle the new serious challenge of AI. Though Taiwan is not yet an epidemic area of AI, it is important for us to be well prepared to confront it. Given that prevention is more important than treatment. It is essential that we try our best to build up an efficiently preventive system for AI. This study aims to investigate what is most important and critical in the preventive system. More specifically, what is a priority to do in such a preventive system, especially in a limited condition of budgets and human resources? According to the five stages of crisis management proposed by Mitroff (1988) (see page 35), the current study focuses mainly on operations in the second stage, preparation and prevention of crisis. In terms of analytic hierarchy process (AHP), it designs a questionnaire to systematically interview 12 doctors. Since four of them are outliers when the consistency test is considered, results are based primarily on the opinions of the remaining 8 doctors. The results are summarized as follows. 1. Before the crisis comes, both ¡§the training of doctors and nurses¡¨ (weighted value = 0.3195) and ¡§the regularization of preventive process¡¨ (weighted value = 0.2978) are most important. 2. The regularization of preventive process (weighted value = 0.3066) is most economic in the limited condition of budgets that is available to the preventive operations. Accordingly, it is a best way to regularize the individual operations and spread the concept of the regularization. 3. The training of doctors and nurses (weighted value = 0.3513) is most important in the limited condition of human resources, that recently appears gradual reduction among hospitals. That is, by means of rehearsal of related operations and of training courses, the crew in a hospital can have an understanding of AI spreading in a short period of time. 4. In consideration of hard equipments, the doctors to be questioned hold similar opinions, as mentioned above. Apparently, the mastery of various preventive operations in the preventive system plays a critical role in that whether the AI crisis will continue to develop. 5. Only in consideration of the effects of prevention, the training of doctors and nurses is also most important. In conclusion, the experts all think that the training of doctors and nurses is a priority, regardless of in what conditions. The findings of the study hope to provide references for other hospitals by manifesting the order of the importance of different preventive operations in the preventive system.