Moreover , the special expression of the moment , the second moment and variance with de moivre ' s death rate were given . finally , considering abrupt event ' s effect on interest , we established the models of the random rate of interest jointly by gauss process and poisson process , wiener process and poisson process or o - u process and poisson process , also gave the moment , the second moment and variance of the payable present value under the three cases . moreover giving the special expression of the moment , the second moment and variance with de moivre ' s death rate 对于连续型情况,随机利率分别采用gauss过程、 wiener过程和o - u过程建模,分别给出了给付现值的一、二阶矩和方差,并在demoivre死亡律假设下得到了矩的简洁表达式;考虑到突发事件对利率的影响,又对随机利率采用gauss过程、 wiener过程和o - u过程分别与poisson过程联合建模,分别给出了给付现值的一、二阶矩和方差,并在demoivre死亡律假设下得到了矩的简洁表达式。