責任保險在國內之概念只限於對被保險人因負有賠償責任所造之賠償金額 的損害由保險人填補，然而責任保險之機能除填補賠償責任損害作用外， 應可經由新的理念結合使之包括權利保護作用以擴張責任保險的作用；另 一方面，責任保險不同於其他損害填補型保險之處在於其運作係在保險人 、被保險人與被害人之間進行，以債之相對性而言，保險人對於被保險人 與第三人間之責任關係並無介入權，但此一觀念之貫徹對責任保險關係之 進行似有造成障礙之虞，基於保險人就責任關係所具密切利害關係及確保 保險賠償額適當之觀點實應容許其參預之權，而在防禦義務與參預權的交 互作用下，其已進而提供重行整合責任保險所涉三方關係的契機。 / In order to expand the functions of liability insruance, an liability insurer not only provide indemnity to the insured when the insured is liable for the third party's bodily injury or property damage but also defend any suit seeking those damages. How to establish an liability insurer's duties to defend and settle from the point of insurable interest is what this thesis manages to deal with. Because an liability insurer will pay damages for which the insured becomes legally responsible, the insurer should have the rights to defend and settle the suit. Only by doing so, can we balance the interest between the insurer and the insured. Furthermore, if we can take good advantage of an insurer's duties and rights to defend and settle, the process of running liability insurance will be simplized.