China Currency Manipulation Act of 2008 - Directs the Secretary of the Treasury to: (1) make an affirmative determination that the People's Republic of China (PRC) is manipulating the rate of exchange between its currency and the U.S. dollar; (2) establish and report to Congress on a plan of action to remedy such currency manipulation; (3) initiate expeditiously bilateral negotiations with the PRC to ensure that it regularly adjusts the rate of exchange between its currency and the U.S. dollar in order to permit effective balance of payment adjustments and eliminate unfair competitive advantage in trade; and (4) instruct the Executive Director to the International Monetary Fund (IMF) to use the U.S. vote to ensure that the PRC takes such action to achieve such goals.