The　combination　of　drug　and　gene　strategies　for　cancer　therapy,　has　exhibited　greater　effectiveness　than　drug　or　gene　therapy　alone.　In　this　paper,　a　coil-comb　shaped　polycationic　brush　was　used　as　a　multifunctional　carrier　for　co-delivery　of　drug　and　gene.　The　side　chains　of　the　comb　block　of　the　brush　were　composed　of　cyclodextrin　(CD)-containing　cationic　star　polymers,　with　a　super-high　density　of　positive　charge.　Doxorubicin　(DOX)　could　be　loaded　into　the　cavity　of　CD　polymers　to　form　DOX-loaded　nanoparticles　(DOX-NPs)　and　the　p53　gene　could　be　subsequently　condensed　by　DOX-NPs.　The　obtained　DOX-NPs/pDNA　complexes　were　less　than　150　nm　in　size,　and　so　could　transport　DOX　and　the　gene　into　the　same　cell.　The　complexes　performed　well　with　regards　to　their　transfection　efficiency　on　MCF-7　cancer　cells.　As　a　result,　enhanced　cell　growth　inhibition,　with　decreased　DOX　dosage　was　achieved　due　to　the　synergistic　effect　of　co-delivery　of　DOX　and　the　p53　gene.　This　finding　provides　an　efficient　approach　for　the　development　of　a　co-delivery　system　in　combination　therapy.