China has the largest population in the world.The large population has caused many problems.For example,in the contryside people's living conditions are not very good.Because there are two or more children in one family and not every child can get a chance to recieve a education.Most of the cities are more crowed than before,and the traffic is much heavier.What's worse,It's quite difficult for a lot of people to find jobs.luckily,china has taken many measure.Such as one-child policy to control the population,Thanks to the policy,the growth of population in china has been controlled.