We propose a new way of browsing bilingual web sites through concurrent browsing with automatic similar-content synchronization and difference-detection facilities. Our prototype browser system is called the Bilingual Comparative Web Browser (B-CWB) and it concurrently presents bilingual web pages in a way that enables their content of the Web pages to be automatically synchronized.The B-CWB allows users to browse two web news sites concurrently and compare the similar news articles written in different languages (English and Japanese). The major characteristics of the B-CWB are its content synchronization and differnce detection: Content synchronization means that user operation (scrolling or clicking) on one web page automatically invokes not necessarily same operations on the other web page to preserve similarity of content between the two web pages. For example, scrolling a web page may involve passage-level similarity retrieval on the other web page. Clicking a web page (and obtaining a new web page) invokes page-level similarity retrieval within the other web site pages through the use of a English-Japanese dictionary. Difference detection means that the B-CWB analyzes two similar web pages shown concurrently to discover the several "differences" between them. This facility is important in comparing two news articles that report the same affairs.