A　modeling　method　of　variable　stiffness　composite　structures　(VSCSs)　with　curved　fiber　trajectories　has　been　developed.　The　fiber　trajectories　are　aligned　in　the　direction　of　maximum　principal　stress,　and　the　VSCSs　with　variable　fiber　orientation　and　the　variable　fiber　volume　fraction　are　modeled　on　the　basis　of　these　trajectories.　A　material　property　degradation　method　taking　into　account　the　heterogeneity　of　material　properties　of　the　VSCSs　is　used　to　predict　the　ultimate　load　and　model　the　progressive　failure　for　a　composite　plate　with　a　hole　under　tensile　loading.　It　is　shown　that　a　transition　from　rectilinear　reinforcement　to　curvilinear　results　in　an　increase　in　the　ultimate　load　of　the　plate.　The　opportunity　for　simulation　of　a　continuous　fiber　path　for　the　VSCSs　is　presented,　and　the　path　could　be　used　to　produce　the　VSCSs　by　additive　manufacturing　(3D　printing).