因果关系作为侵权责任不可或缺的构成要件，不仅与责任的成立息息相关，同时也影响着责任范围的确定，因此因果关系理论在侵权法领域具有重要地位，也具有非常深刻的现实意义。当今社会不断出现越来越复杂的案件，其中，第三人的介入就常常发生，在这种情况下初始行为与损害结果之间的因果关系是否仍旧成立就需要讨论介入行为是否导致了因果关系链条的中断，因此，第三人介入导致因果关系中断是一个重要课题。 在研究这一课题时，通过对大陆法系和英美法系因果关系理论发展研究成果的总结，以及对大量文献的分析，能够明确这一课题的研究工作应当适用的理论是相当因果关系学说，并且还应适当考虑法律政策的因素，这是课题讨论的必要前提。 探讨第三人介入导致因果关系中断的问题，首先需要搞清楚因果关系中断的概念和特征，将其与相似概念-假设的因果关系和超越的因果关系进行比较能够更为清晰地掌握因果关系中断。其次要研究的是第三人的介入行为在满足什么样的条件下可能中断因果关系，以及因果关系被第三人中断之后的法律后果，这些内容需要从国内外的法规和司法实务做法中寻找答案。 在对前述问题一一解答之后，应当进行重点讨论的就是第三人介入与因果关系中断的类型分析了。通过对国内外大量案例判决及经典判例的梳理，不难发现导致因果关系中断的第三人介入行为分为故意介入与过失介入两类，因为原则上只有具有主观过错（即故意或过失）的行为才可能成为替代原因而中断初始因果关系。将案例判决进行归类整理之后，可以看出故意和过失这两种介入行为造成因果关系中断的可能性是完全不同的，在同等情况下，第三人的故意介入往往更易于中断初始因果关系链条，而过失的介入必须在满足一定条件的前提下才可能造成因果关系的中断，这一判断是以因果关系的相当性和不可预见性理论作为其重要标准的。在普遍规律的前提下，当然也存在着一些特殊情形，对这些特殊情形的分析更加验证了相当因果关系理论对判断第三人介入导致因果关系中断的重要性。 通过对第三人介入与因果关系中断这一课题的探讨，希望能够为司法理论界深入研究侵权法因果关系贡献一丝力量。

As tort liability components, causality is important to tort responsibility, so causality theory is in a significant position. In today's society, more and more complex cases appear, among which, the intervention of the third person often occurs. In these cases, we must make sure that whether the intervention interrupt causality. Through analysis of a large number of documents and cases, I know that we should use adequate causality theory to research the question, at the same time, considering legal policy. At first, we must figure out what is interruption of causality and its feature. So I choose to compare it with its similar theories-the assumption of causality and surpass causality. Then we should make sure what conditions may break off causality and its legal consequences. After that, now the topic shall be the third person intervention and analysis of the types of causality interruption. Through a lot of domestic and foreign cases, it is not difficult to find that only the behavior of fault in principle may interrupt causality. And we can see that in same circumstances, behavior of a deliberate person is easier to break the causality chain and the negligent behavior meeting certain conditions may interrupt causality. This judgment depends on the adequate causality theory. Beyond the standard, of course, there is also some special cases, which is a further proof to that the adequate causality theory is appropriate to the study of this topic. Through the research on the third person intervention and interrupt of causality, I hope the conclusion can be helpful to Chinese judicial theoretical study on causal relationship.