China and Japan are witnessing expanding cooperation on energy conservation and environmental protection, a Chinese official said Wednesday, days before the opening of the fourth China-Japan energy conservation forum.

China and Japan are going to sign cooperation agreements on more than 40 energy-saving and environmental protection projects at the forum, slated for Nov. 8 in Beijing, said Xie Ji, deputy head of the energy conservation and environment protection department of the National Development and Reform Commission (NDRC).

The two countries signed a total of 34 contracts at the previous three forums. First initiated in 2006, the forum is co-hosted by the NDRC, China's Ministry of Commerce, and Japan's Ministry of Economy, Trade, and Industry.

Xie said the coming fourth forum would focus on topics such as policies on energy conservation and emissions reduction, recycling economy, sea water desalination, water treatment, power generation and China-Japan long-term trade.

More than 400 representatives from the political, business and academic circles of the two countries will attend the forum.