This study test how two distinguishable frames identified from Mainland Chinese online coverage of Taiwan's 2004 presidential election campaign influenced U.S. and Chinese audiences' event perception and attitudes toward Mainland-Taiwan relations. Employing 2x2x3 between-subjects experiment, this study highlights the moderating effects of issue familiarity. Findings show a significant impact of framing intensity on the event perception of those who may not be familiar with the topic, in addition to a significant influence exerted by frame type on event participation. The roles of familiarity and other factors involved in framing effects on issue attitudes are also discussed from a comparative perspective.