Abstract: Source term and off-site consequences in the case of a station blackout (SBO) accident are analyzed for QinShan Nuclear Power Plant (QSNPP) using MELCOR and MACCS codes. Doses of inhabitants are biggish, but the doses are not very large and few off-site early health effects would occur. Several kinds of emergency protective actions are evaluated using MACCS. According to the evaluation, the best emergency protective action is sheltering after the containment leak and quick evacuation after the containment failure by overpressure if the containment failure is unavoidable.