Based on the data of GDP and population during the period 2003-2008, the energy demand in 2020 for industrial and residential energy in Dongtan area of Chongming Island was forecasted through the scenario simulation, and together with other research material, the development status of renewable energy was also detected. The results show that: 1) Under the low and high scenarios (LS and HS), the industrial energy demand in 2020 will respectively reach 127944 tce (ton of standard coal equivalent) and 401817 tce, which are 1.9 and 6 times that in 2008, respectively. While the residential energy demand under LS and HS in 2020 differentiates little from each other, and it is about 50% of increment compared with the current consumption. 2) The industrial and residential energy demand in 2020 under the moderate scenario (MS), which is more reasonable to energy prediction, will be respectively 264881 tce and 32.5 million kwh, and with the average annual increase rate of 12.1% and 3.5% from 2008 to 2020, respectively. 3) The development degree of the wind energy and solar energy in Dongtan is currently considerably low, which accounts for less than 1% in the energy structure. the findings suggest that the energy scheduling and planning should be implemented to coordinate the balance between energy demand and energy supply in the future; meanwhile, it is necessary to adjust the energy structure and develope renewable energy such as wind and solar energy in the next decades to address environmental problems resulting from the consumption of a mass of fossil fuels.