Drawing upon issue ownership theory, this paper explores the relative effectiveness of political ads featuring issues owned by the party of the candidate and ads featuring issues owned by the opposing party in the 2008 presidential campaign in Taiwan. Experiment one tests four competing hypotheses. The results show supports for the superior effects of ads featuring owned issues among non-partisans. Experiment two examines whether the two comparative appeals, I-am-better-than-the-competitor or the-competitor-is-worse-than-me, moderate the effectiveness of ads featuring issues owned by the party. The results demonstrate that, when ads feature owned issues, the two appeals do not generate different effects; whereas when ads feature issues owned by the opposing party, I-am-better-than the competitor appeal is more effective.