A　very　simple　and　facile　method　of　synthesizing　Pt　nanoparticles　(NPs)　deposited　on　Pt-bpy　metal-organic　complexes　(bpy　=　4,4′-bipyridyl)　has　been　developed.　No　additional　capping　agents　or　solid　supports　are　required.　The　formation　of　Pt　NPs-bpy　composites　was　largely　dependent　on　the　molar　ratio　of　metal　to　bpy.　When　the　molar　ratio　of　Pt　to　bpy　is　more　than　1:2,　Pt　NPs　were　deposited　onto　the　surface　of　the　formed　Pt-bpy　complexes.　This　was　demonstrated　by　transmission　electron　microscopy,　X-ray　diffraction,　and　X-ray　photoelectron　spectroscopy.　When　the　molar　ratio　of　Pt　to　bpy　is　less　than　or　equal　to　1:2,　Pt　NPs　are　difficult　to　form.　Moreover,　the　Pt　NPs-bpy　composites　were　used　as　a　heterogeneous　catalyst　toward　the　hydrogenation　reaction　of　the　nitroarenes　bearing　different　steric　and　electronic　groups.　The　catalyst　could　be　recycled　for　at　least　six　cycles　without　catalytic　activity　loss.　©　2017　American　Chemical　Society.