DHTML accessibility is being standardized by W3C, which provides metadata for UI widgets commonly implemented by HMTL and JavaScript. However it is difficult to check that webpages always have correct metadata according to the standards of DHTML accessibility since UI widgets can be updated by JavaScript programs. Thus we propose a technique for checking accessibility of UI widgets. In this check, we use static program analysis techniques so that we can check accessibility without executing a program. In addition, we developed a prototype system based on the proposed technique and applied it to a simple DHTML application.