Today, China has become the world＇s second largest pollution source of CO2. Owing to coal-based energy consumption, it is estimated that 85-90% of the SO2 and CO2 emission of China results from coal rise. With high economic growth and increasing environmental concerns, China＇s energy consumption in the next few decades has become an issue of active concern. Forecasting of energy demand over long periods, however, is getting more complex and uncertain. It is believed that the economic and energy systems are chaotic and nonlinear. Traditional lineal system modeling, used mostly in energy demand forecasts, therefore, is not a useful approach. In view of uncertainty and imperfect information about future economic growth and energy development, an uncertain dynamic system model, which has the ability to incorporate and absorb the nature of an uncertain system with imperfect or incomplete information, is developed. Using the model, the forecasting of energy demand in the next 25 years is provided. The model predicts that China＇s energy demand in 2020 will be about 2,700-3,000 Mtce, coal demand 3,500 Mt, increasing by 128% and 154%, respectively, compared with that of 1995.