心肌梗塞是一個具有生命威脅且會隨時復發的疾病，因此病人有許多不確定的事情須要去面對及因應。本研究之主要目的為探討心肌梗塞病人不確定感受對採取因應行為的影響。研究問題為心肌梗塞病人於住院期間的：(1)病人所感受到的不確定感程度及來源；(2)病人採用的因應行為；及(3)病人不確定感受與所採取因應行為的相關性。本研究的對象為教學醫院中65位心肌梗塞病人，採用的量表為中文版Mishel疾病不確定感量表及Vitaliano等人所發展的修正後的因應行為量表。本研究結果發現心肌梗塞病人於住院期間有中等程度的不確定感，不確定感的主要來源有八項，其中七項是疾病相關事件不明確所引起的，“我不知道下一步會發生什麼事”為病人感覺最不確定的事項，且教育程度低的病人，其不確定感較高。另外病人最常用的是以問題為中心的因應行為，其中使用“按步就班”的人最多。最重要的，本研究發現當病人不確定感高時，較常使用逃避及願想式的情緒性因應行為，換句話說，不確定感會阻礙病人使用問題性因應行為來解決問題。本研究結果可讓護理人員感受到不確定感是值得重視的護理問題，更進一步的，本研究結果可協助護理人員照護心肌梗塞病人時評估不確定感、因應行為，進而設計適當衛教，以有效地幫助病人調適，達到最佳健康狀態。 Myocardial infarction is a life threatening disease and prone to recur. Patients with myocardial infarction experience a great deal of uncertainty. The purpose of this study was to examine the impact of this uncertainty on patients’ coping behaviors. Three questions were addressed in this study: (1)the degree and sources of uncertainty, (2)the coping methods used, and (3)the relationship between the degree of uncertainty and coping methods. Sixty-five patients in a teaching hospital participated in this study. Chinese versions of Mishel’s Uncertainty in Illness Scale and the Revised Ways of Coping Checking List were used to measure the perception of uncertainty and coping methods respectively, The results showed that patients with myocardial infarction perceived moderate uncertainty.Among the eight sources of uncertainty, seven were due to ambiguity related to the illness. Furthermore, the fear of not knowing when to expect things will be done was found to be the major source of uncertainty. Subjects with lower education had higher uncertainty levels. To cope with the uncertainty, patients used problem coping more often than emotion coping methods. More specifically, among the problem coping behaviors, taking one step at a time was the main behavior used. Most importantly, the results showed that when patients perceived high levels of uncertainty, they often used avoidance or wishful thinking as coping behaviors. In other words, high levels of uncertainty inhibited patients from adopting problem-solving methods to cope positively with the illness. The findings of this study may help nurses be more aware of the influence of perceived uncertainty on the recovery of patients. Furthermore, the results can be used to help nurses assess uncertainty perceived by patients, to develop better health education, and to help patients utilize appropriate coping behaviors in order to obtain optimal health.