All Taiwan listed companies have adopted IFRSs since 2013. The Financial Supervisory Commission required financial information to be prepared based on both ROC GAAP and IFRSs in 2012. This paper examines whether relevance of comprehensive income changed during the mandatory transition from ROC GAAP to IFRSs in Taiwan. The empirical results include four parts: (1) under IFRS and ROC GAAP, the difference of other comprehensive income (OCI) is not incrementally value-relevant (2) only in the sub-sample, the incremental valuation of unrealized income on available-for-sale financial assets differences between IFRSs and ROC GAAP is significantly negative; (3) the adjustment in earnings is incrementally value-relevant, and the earning under ROC GAAP is significantly more value relevant than under IFRSs, the book value of equity under IFRSs is significantly more value relevant than under ROC GAAP and (4) in the earning-return equation models, the difference of OCI under IFRSs and ROC GAAP is incrementally value-relevant in the sub-sample of OTC companies.