The　effects　of　nanoparticles　deposition　on　the　nanofluid　flow　and　convective　heat　transfer　characteristics　in　the　vertical　tube　were　studied　experimentally.　Flow　and　heat　transfer　characteristics　of　Al2O3/H2O　nanofluid　in　the　vertical　tube　were　studied　under　different　nanoparticle　concentration　in　the　case　of　nanoparticles　deposition　and　no　nanoparticle　deposition　respectively.　The　results　showed　that　nanoparticles　deposition　have　significant　effects　on　the　flow　characteristics　but　the　effect　on　heat　transfer　characteristics　is　not　obvious,　and　with　the　increasing　of　the　nanoparticle　concentration,　the　frictional　coefficient　and　the　heat　transfer　capacity　have　been　significantly　enhanced.　©　2017,　Editorial　Board　of　Journal　of　Nuclear　Power　Engineering.　All　right　reserved.