Pd　nanoparticles　with　a　small　size　of　ca.　6　nm　were　deposited　on　the　surface　of　ZnIn2S4　via　photoreduction　of　Pd　(CH3CN)(2)Cl-2　over　ZnIn2S4　under　visible　light.　The　resultant　Pd-ZnIn2S4　nanocomposites　were　fully　characterized　and　their　catalytic　performance　for　light　induced　N-alkylation　of　amines　and　alpha-H　alkylation　of　ketones　with　alcohols　were　investigated.　It　was　found　that　Pd-ZnIn2S4　nanocomposites　show　superior　catalytic　activity　for　the　alkylation　reactions　via　a　successful　coupling　of　the　photocatalytic　dehydrogenation　of　alcohols　over　ZnIn2S4　with　Pd-based　hydrogenation.　An　optimum　performance　was　realized　over　0.5　wt%　Pd-ZnIn2S4　nanocomposites　by　synchronization　of　the　rates　of　different　reaction　steps　in　the　tandem　alkylation　reaction.　Ascribed　to　the　small　sized　Pd　nanoparticles,　which　provide　more　active　unsaturated　Pd　atoms,　Pd-ZnIn2S4　nanocomposites　obtained　via　photoreduction　show　superior　performance　as　compared　to　Pd/ZnIn2S4　obtained　via　a　chemical　reduction　using　NaBH4.　This　study　provides　an　efficient　way　to　realize　a　highly　efficient　and　stable　alkylation　of　amines　and　alpha-H　of　ketones　with　alcohols　under　visible　light.　This　study　also　highlights　the　great　potential　of　construction　of　multifunctional　catalysts　for　light　induced　organic　syntheses.