先前研究指出，財報資訊使用者難以使用確定福利計畫制退休金的資訊，其原因可以歸因於退休金會計的複雜性。在後SFAS 158 時期，由於先前僅揭露的退休金負債已認列於資產負債表上，使得退休金資訊的價值攸關性有所提升。然而有研究指出，額外攸關的資訊依然僅在附註揭露中表達，使得XBRL在能否進一步提升該價值攸關上有可以著墨的空間。本研究探討美國SEC XBRL 強制適用是否能提升確定福利計畫制退休金資訊的價值攸關，以及 XBRL財報的特性是否會影響該價值攸關。實證結果發現，美國SEC XBRL 強制適用提升了提撥狀況的價值攸關。另外，實證結果也發現，GAAP 分類標準概念的數量和提撥狀況的價值攸關有負向的關係；延伸分類標準概念的數量和提撥狀況的價值攸關有正向的關係。本研究亦指出，SEC XBRL 強制適用對於提撥狀況價值攸關的提升，及XBRL財報特性對提撥狀況價值攸關的影響，會因為不同階段之 XBRL 採用者而有不同的效果。 / Studies show that the information of defined benefit due its complexity, users may not have the competence to process it. In the post-SFAS-158 period, the previously disclosed liabilities of defined benefit now recognize in the balance sheet. Prior studies have already shown an improvement in value relevance. However, studies suggest the relevant information still presents in footnotes. It leaves a place for XBRL for further improving. In this study, I investigate whether SEC XBRL mandatory adoption improves the value relevance of defined benefit information, also whether the characteristics of XBRL file affect the value relevance of defined benefit. The empirical results show SEC XBRL mandatory adoption improves the value relevance of funded status. Also, the number of GAAP Taxonomy concepts is negatively associated with the value relevance of funded status. Moreover, the number of extension concepts is positively associated with the value relevance of funded status. The additional results show the improvements by XBRL adoption and the influence of the number of GAAP Taxonomy concepts and extension concepts are sensitive to different phases of the adopters.