保險法第六四條告知義務之規範，常為保險契約爭議之所生。尤以保險事故發生後，受益人向保險人請求保險給付時，保險人調閱被保險人之過往病史方發現其業已罹患影響保險人危險估計之疾病後，即據以解除契約。惟現行保險法第六四條第二項但書規定「但要保人證明危險之發生未基於其說明或未說明之事實時，不在此限。」倘若保險事故之發生係非因「故意隱匿或過失遺漏，或為不實說明」之事實所致者，則保險人解除權之行使即受此抗辯之限制。本文即擬以保險法第六四條第二項但書為課題，先就目前現行法適用所生爭議加以論述，繼而再就該項規範之妥適性再行剖析。尤其不實說明之事實如與保險事故發生間不具因果關係時，所生限制或影響當事人契約關係之法律效果更是近來實務見解與相關紛爭時，不易解決之難題。於本文中即參輔德國與日本立法例與相關學說，而提出現有條文規範之缺失與修法建議。

The duty of disclosure in the Article 64 of Insurance Code is said to be the most controversial issue in the legal disputes between insurers and insureds. When the policyholder is in breach of duty of disclosure, the insurer shall be entitled to avoid the contract and retain the right to any premium due even after the insured event. In the case of non-disclosure, however, the remedy to rescind contracts of insurance can be limited in lack of a causal link between the non-disclosure and the insured event. In this work, the author would like to criticize and analyze the problems arising from the remedy of non-disclosure based on several courts’ decisions and a selective survey on the rule of non-disclosure in several countries.