The development of renewable energy is one of the important strategies to reduce global greenhouse gas emissions. Renewable Energy Sources Act (EEG) was taken into effect in Germany since 1st April 2000, in which feed-in-tariff (FIT) for onshore wind, offshore wind, solar radiation, hydropower, geothermal, biomass, landfill gas, sewage gas, mine gas and etc were set while at the same time power transmission and distribution enterprises were obligated to purchase electricity generated from renewable energy. All these enabled renewable energy to be adopted into the German power market. Since then, renewable energy in Germany has developed prosperously and its successful experience has become the role model to the world. The mechanism of renewable energy development in Taiwan is in the initial stage and has a lot to learn from the German experience. Therefore, this study is expected to probe into the FIT mechanism in Germany and its development in relation to environmental policies, economic incentives, and supporting measures, and to explore the investment incentives, risk securities and financing of tariff decision factor and adjustment design. Moreover, the latest international trend of renewable energy development and the strategies to promote FIT in other countries are also included in this study. The results of all the research in this study are important references to set up an operation mechanism of Greenhouse Gas Emission Reduction XI Act (Draft) related regulations and supporting measures. In addition, during the implementation of this study, we collaborated with experts from international research institutes and German think tanks to build a feasible bilateral cooperation mechanism on energy conservation and carbon reduction between Taiwan and Germany. Through the long term bilateral interaction, we expect to achieve our policy goal of renewable energy development and greenhouse gas emission reduction.