Human population has increased repidly There are too many people on earth.that means greater pressures for the earth.Overpopulation is not benefit for living .Almost every country faced the population problem.The population growth brings lots of problem,such as food shorttage.that the land couldn't so many grain,water lacking.As we know,water and food is very important to human.We can't live without them.Cities become more and more crowded,that cause heavy traffic,housing shortage,more and more people losing their jobs.That also puts much pressure on education and environment.The environment polluted by the modern industry.There are many reason for populaton growth.First of all,people want to have a better life.They need to creative their home.They need more people working with them.Second,they want to make life easierby creativing tools,science and technology.The factories are born.People inventedlots of machines.More and more people are needed.Last there are some reason about customs.People prefer boys and girls.Especially in the Chinese countryside.In order to have a boy,they have to produce more children,which causes overpopulation.