According to the mathematical model, it is the substitution rate, age at employment, age at retirement, dependency ratio, life expectancy, mortality rate, population age structure, economic prosperity, inflation, population migration, wage growth rate and interest rate,that influence the revenue and expenditure balance of endowment insurance.

According to the revenue and expenditure balance model of endowment analyses, there are many factors that influence its balance.

On the problem that income unbalances expenditure in the pension insurance funds in our country at present and in the future, this paper applies the mathematical model of partial accumulation balance to make a quantitative and qualitative analysis of the relevant factors influencing payment balance of pension insurance funds.

Forecast for the funds payment balance with actuary principle encompass population,personal account,funds payment and gap forecast.

After the personal account fund is separated from social pool fund in the system of independent account,it runs in the model of "full account" ,accumulates constantly and faces the fund s balance of income and expenditure .

Conclusions:the way of effective payment is an important measure,which ensures medical insurance fund balance of payments.