The　impact　of　the　mechanical　properties　of　nanomedicines　on　their　biological　functions　remains　elusive　due　to　the　difficulty　in　tuning　the　elasticity　of　the　vehicles　without　changing　chemistry.　Herein,　we　report　the　fabrication　of　elasticity-tunable　self-assembled　oleanolic　acid　(OA)　nanoconstructs　in　an　antiparallel　zigzag　manner　and　develop　rigid　nanoparticles　(OA-NP)　and　flexible　nanogels　(OA-NG)　as　model　systems　to　decipher　the　elasticity-biofunction　relationship.　OA-NG　demonstrate　less　endocytosis　and　enhanced　lysosome　escape　with　deformation　compared　to　OA-NP.　Furtherin　vitroandin　vivoexperiments　show　the　active　permeation　of　OA-NG　into　the　interior　of　tumor　with　enhanced　antitumor　efficacy　accompanied　by　decreased　collagen　production　and　eight-　to　tenfold　immune　cell　infiltration.　This　study　not　only　presents　a　facile　and　green　strategy　to　develop　flexible　OA-NG　for　effective　cancer　treatment　but　also　uncovers　the　crucial　role　of　elasticity　in　regulating　biological　activity,　which　may　provide　reference　for　precise　design　of　efficient　nanomedicines.　©　2021　American　Chemical　Society