Officials signed agreements on 51 projects in energy conservation and environmental protection at during an investment forum in Beijing, China's official Xinhua news agency reports.
The projects outline a range of issues from energy-saving standards to expanding thermal power efficiency, the report adds.
Beijing said that, with China's expanding economy and Japan's technological advancements, bilateral cooperation made strategic sense. Tokyo said it recognized the economic opportunities of working with China and the bilateral need to protect the environment.
Japan was forced to review its energy mix following an earthquake- and tsunami-triggered nuclear meltdown at its Fukushima nuclear power plant in March.
An October report prepared by the National Development and Reform Commissions Energy Research Institute, in cooperation with the International Energy Agency, determined China could have 1,000 gigawatts of wind energy in its grid by 2050. This represents a 16 percent increase from current levels.
The Organization of the Petroleum Exporting Countries in an October report said it expected lower energy demand from Asia as the Chinese economy slows.