According to the operation mechanism of New Rural Social Endowment Insurance (NRSEI) system,this paper establishes an actuarial model of individual account and predicts the gap between income and expense of the NRSEI individual accounts pension with the combination of population life distribution model.The result shows that rural residents who participate in the NRSEI will gain more profits than direct deposit money in banks.Therefore,the NRSEI deserves participation.There are many kinds of ways to participate in the NRSEI.Rural residents can choose ages beginning their participating,level of payment and years of payment according to their actual ages,participating preferences,income level and expected anticipations.There exists a gap of 21% in the NRSEI individual accounts.But the gap only accounts for a relatively small proportion of GDP,and it increases slowly.Therefore,the government has a plenty of time to improve the NRSEI system.Unreasonable system contributes to the gap of new rural social endowment insurance.Therefore,in order to ensure the sustainable development of the NRSEI fund,this paper proposes that we should timely adjust the coefficient of individual account annuities and retirement age,or bring individual account annuities to market-based investment operations.