Abstract: In order to accurately analyze the durability of concrete structure under the chlorine erosion， the parameters randomness is studied for the service life of concrete structure by use of the reliability stochastic finite element method. The parameters include concrete material parameters， geometrical parameters and environmental parameters. First of all， based on the serviceability limit state equation of the concrete structure exposed to the marine environment， the stiffness recursive equation and iteration algorithm are established by perturbation stochastic finite element method (PSFEM) and optimization algorithm. The service life of the concrete structure is predicted based on the preset reliability level. Then， sensitivity of random parameters is studied for service life using sensitive coefficients. This new method is applied to the durability analysis of a marine concrete embankment. The research results have shown that the concrete cover thickness has the greatest effect upon the concrete structure durability, to which should be paid a special attention in the design, and that the parameter randomness has a significant influence on the service life of the concrete structure. Once neglecting this parameter randomness must result in unsafe design results.