This study focuses on the paragraph 2 of article 47 in Taiwan's Presidential Election Act. This clause prohibit from publishing opinion polls before the presidential election. It limits, during ten days, to exercise liberally the freedom of expression. The first part of this paper examines the constitutional legality of this prohibition. It examines how the exercises democratic election co-exists with the restriction on the exercises of the freedom of expression from a comparative perspective. In the second part, this paper investigates the current defects in the article 47 of Taiwan's Presidential Election Act and ends with some propositions for future amendment.