Chinanews, Beijing, December 14 – At the beginning of China's reform and opening-up in 1978, the shifting population in the country was only 2 million. Now the figure has increased to 140 million, taking up 10% of its total population, at an annual rate of 6 million – 8 million.Eastern China and big Chinese cities have benefitted greatly from shifting population, but large shifting population has also caused many environmental and resource crises in these areas, not to mention the pressure upon public administration and social service.It is natural for China to have large shifting population during its fast industrialization and urbanization process. Most of such shifting population are migrant workers from rural areas, aged between 16 and 40. Some of them are the children of the first-generation shifting population. Not many of them have been properly trained for professional work, thus they usually choose to work in building or decoration industries, which require more physical strength than job skill.However, as the polarization between town and country still exists and the urbanization process still continues, there will emerge larger shifting population in China in the future. It is estimated that 250 million more people will migrate from rural areas to cities before 2015.