The Decision of Strengthening Population and Family Planning Work and Stabilizing Low Fertility Rate by the Central Committee of CCP and the State Council has epoch-making significance in practice and theory.To stabilize low fertility rate shall enhance demographic studies,master the numerical relations and limitations.There will be a certain side effect of keeping low fertility rate.How ever,one should scientifically and overall weigh up the gains and losses.Generally speaking,the advantage outweighs the disadvantage.Keeping low fertility rate is good for healthy development of population,resources and environment,and social sustainable development.