This pa야r 15 an attempt to aα:ount for the uncertainty of the residual strength in the reliability analysis of structural systems. For this purpose the stochastic finite element meth여(SFEM) is li띠<ed to the system reliability analysis pr'∞edure. The stochastic finite element is known to be able to a more explicitly ∞nsider the effect of uncerainties of material and g∞metric variables on those of load effects in structural analysis prlα:edure. The method has been applied to system as well as comφnent reliability analysis of a plane structure. Comparison of the results by the present approach is made with the method in which the residual strength of f려led ∞mponent is treated as deterministic variable. Several case studies have been carriE최 to show the effect of uncertainty in residual strength of a member after failure. Is has been ∞nform어 that reidual strength very much affect the system reliability level. It can be, hence, ∞ncluded that the uncertainties in the αlSt-ultimate behaviour may have to be t혀<en mto account in the system reliability analy의s for a better a s않ssment of the system reliability especially for a struct파e of which member behaviour is m여ell어 as asemi-brittle model.And then the sto .:hastic finite element method can efh디ently evaluate the system reliability.