Life insurance is one of the most important insurance fields that plays an effective role in financial development, and consequently in economic growth. A review of the history of this insurance field indicates that life insurance has been one of the earliest insurance coverages used in Iran, but its progress has been so slow that it has not been able to keep up with other types of insurance coverage in Iran. Therefore, according to the importance of this issue, the purpose of this study was to investigate the effective factors on developing life insurance industry in Iran and in the development countries during the period of 1985-2014. The results of estimation of coefficients revealed that, among the variables under consideration for developed countries, level of education, urbanization rate, interest rate, and inflation, respectively, had the highest effect on dependent variable (insurance penetration), and for Iran, life expectancy, real GDP, level of education, urbanization rate, interest rate and inflation, respectively, had the highest effect on dependent variable.