Abstract:A new interval stochastic finite element method based on the interval factor method and random factor method is given and the analysis of structural dynamic characteristic for interval stochastic truss structures is presented. Considering the interval randomness of the structural physical parameters and geometric dimensions simultaneously, the structural stiffness and mass matrices were constructed based on the interval factor method and random factor method;from the Rayleigh’s quotient of structural vibration,the structural interval random dynamic characteristic was obtained by means of the interval arithmetic;the interval numeric characteristics of dynamic characteristic were then derived by using the random variable’s moment function method and algebra synthesis method.Two numerical examples were provided to illustrate the validity and feasibility of the present method.