It is shown in the chart that significant changes occurred concerning the urban population in China between 1990 and 2010. Specifically, the number of urban population was 300 million in 1990, and it rose to 700 million in 2010. As to the number of rural population, it displayed a reverse trend, varying from 810 million to 690 million during the same period.
Obviously, the phenomenon reflected in the chart stems from a hosts of factors; in my view, the following three are worth discussing. Firstly, economic advancement has, to some extent, led to the phenomenon ,with better living standards, a number of people are looking for a good living environment(寻求好的生活环境). Secondly, the advancement of science plays a crucial role, Thanks to convenience and efficiency brought about by technological breakthroughs, which enables people to seek better career opportunities（可以使人们找到好的工作机会）. Thirdly, this phenomenon has a connection with the shift to people's attitudes , according to the findings from large-scale studies, which enable people to shopping and living conveniently（可以使人们方便的购物和生活）.
To sum up, what is reflected int the chart does not occur randomly. I firmly believe that trend will persist, influencing both the individuals and the whold society in the long run.