A method of frequency reliability sensitivity for dynamicstructural systems is presented in the paper based on the frequencyreliability theory. With the criterion that the difference in value betweenthe natural frequency and driving frequency is controlled, the reliabilitymode and the safety probability of the random systems are then defined asseries mode to perform the frequency reliability sensitivity analysis. Acase of resonant problem in the dynamic structural systems is carried out byusing the random perturbation technique, the reliability theory andsensitivity approach. Numerical results have demonstrated that the proposedmethod is efficient and accurate. This scheme is helpful for the design andoptimization of dynamic structural systems.