Based on the stiffness reliability-based design theory and sensitivity analysis method,the stiffness reliability-based sensitivity analysis of beam structure with arbitrary distribution parameters is extensively researched and a numerical method for stiffness reliability-based sensitivity analysis is presented.The variation regularities of reliability sensitivity are obtained and the effects of design parameters on reliability of beam structure are studied.The method presented in this paper provided the theoretic basis for the stiffness reliability-based design of beam structure with arbitrary distribution parameters.