According to demograghic statistics , China has been placed in a very interesting situation.
My maternal grandparents have five children and my paternal grandparents also have five children. But because of family plan policy that Chinese government implements, I am the only child my parents have . In my case, I hope that I can have two or three children of my own, it's better to have one boy and one girl. One kid in one family is not fair to children, in our generation, at least we have cousin, but next several generation whose parents effected by family plan will be alone after their parents pass away.
China have about 1.3 billion people (1,321,851,888 as of mid-2007) now, hugh population bring lots of problems such as environment can not afford whole demand of society, unbalance sex ratio and higher class polarizes with lower class. As a result, Chinese government implements famliy plan to control increasing population. So far from starting family plan, it helped effectively.
Generally, the population in rural areas is more than population in urban areas. That is because people who live in urban areas have more chances to get high education, they realize that having children means a lot of responsbility, so they tend to work hard for a higher level life condition and have less children. In contrast,people who live in rural areas have lower education so that they think in traditional way that big family with more offspring (especially male offspring) means happiness and successful life . But in fact, many rural family can not afford these children due to poor financial condition. In addition, choosing sex of babies artificially lead to unbalance sex ratio that result every 119 boys are born for 100 girls, it means that millions of men may live as frustrated bachelors by 2020. However, increasing transient population are changing this condition and creat many new problems.
China population is the most important part of total amount population in the world. We will see what will happen in the future.