我國與日本在金融海嘯期間同樣採取融券放空限制相關措施，本文分別從理論面與政策面歸納整理，並作實證分析兩國政府採行禁止融券放空的政策效呆。政府採行禁止融券放空相關措施，將會影響股市漲跌與成交量，加劇股市振幅，進而影響股市市場機能的正常運作;由於在壓抑股市跌幅的政策效呆上，短期效呆有用，但長期則失去政策意義，正如國外學者證明，政府不宜採行任何干預市場機制的措施，影響市場正常運作，政府應就有利於市場運作的事項進行改革。

Both the Taiwanese and Japanese government adopted the relevant banned short selling under the financial tsunami. This paper analyzes the short-selling constraints from the theoretic and practical perspectives and performs an empirical study on the policy effectiveness of complete short-selling bans Both Taiwan and Japan. This paper finds that the constraints on short selling affect trading volumes， and enhance the fluctuations of the market. As a result， the market mechanism cannot operate normally. Although the policy of suppressing market declines sees results in a short period of time， the policy loses its meaning over the long term. Itis the consistent result with scholars that the government should not adopt any measures to intervene in the market mechanism. In fact， the government should do good reform beneficial to market operations.