The　addition　of　nanoparticles　to　a　base　fluid　(i.e.,　nanofluids)　is　an　effective　strategy　to　achieve　a　higher　thermal　conductivity　of　a　fluid.　In　a　common　nanofluid,　the　suspended　nanoparticles　are　mostly　symmetrical　spheres.　In　the　present　paper,　we　propose　to　add　Janus　nanoparticles　into　a　fluid　(termed　as　Janus　nanofluids),　to　further　enhance　the　thermal　conductivity　of　nanofluids.　By　using　molecular　dynamics　simulations,　it　is　found　that　the　thermal　conductivity　can　be　distinctly　improved　by　introducing　Janus　particles　into　the　nanofluids　in　contrast　with　common　nanofluids.　Based　on　the　calculation　results　of　the　molecular　radial　distribution　function　around　the　nanoparticle,　and　the　diffusion　coefficient　of　the　base　fluid　and　the　Janus　nanoparticle,　the　enhancement　in　the　thermal　conductivity　of　Janus　nanofluids　is　attributed　to　the　enhanced　Brownian　motion　of　Janus　nanoparticles,　which　increases　the　probability　of　inter-molecular　collisions　and　leads　to　enhanced　energy　transfer　in　nanofluids.　The　Janus　nanofluids　proposed　in　this　work　provide　insights　for　the　design　of　nanofluids　with　high　thermal　conductivity.　©　The　Royal　Society　of　Chemistry.