摘要： 国内学界对西方国家紧急避险的理论介绍较为欠缺。大陆法系和普通法系关于紧急避险的立法理念和司法实践不同，但在法律评价的思路方面却异曲同工，都承认紧急避险在必要的限度内是一种正当的合法行为(权利)，也可以成为法律上免责的事由(抗辩理由)。对大陆法和普通法中丰富的紧急避险理论进行介绍和分析，可以为我国的紧急避险理论提供一种“外部视角”，以弥补当前法律体系对紧急避险行为性质认定的不足，为司法实践提供参考依据。

关键词: 紧急避险, 权利, 免责事由, 犯罪

Abstract: Domestic academics did not pay much attention to the introduction and analysis of western theories ofnecessity. The continental law system and the common law system had different ways of lawmaking and legalpractices. However, both of them have recognized the reason of necessity. Necessity can be justified as a special right，or a justified defense. This article will introduce and analyze western theories of necessity，to fillthe gap in domestic academic debate，as well as to provide a reference for Chinese future legal practices.

Key words: Necessity, Right, Excuse, Criminal Offences