http://www.chinadaily.com.cn/english/doc/2004-04/24/content_325958.htm It doesn't say which method they use or what they use to power the plants. Nuclear power is one option.
According to the seawater freshening programme, China will upgrade its capability to desalinate 100,000 to 150,000 tons of seawater each day in 2005 to satisfy the daily demands for about 7. 5 million people.
The daily amount of desalinated seawater will then increase to 300,000 to 400,000 tons to meet the consumption of more than 20 million Chinese by 2010, compared to China's current 40,000 tons of desalinated seawater.