Thermodynamical　properties　of　charged　AdS　black　holes　with　a　global　monopole　still　remain　obscure.　In　this　paper,　we　investigate　the　thermodynamics　and　phase　transition　of　the　black　holes　in　the　extended　phase　space.　It　is　shown　that　thermodynamical　quantities　of　the　black　holes　exhibit　an　interesting　dependence　on　the　internal　global　monopole,　and　they　perfectly　satisfy　both　the　first　law　of　thermodynamics　and　Smarr　relation.　Furthermore,　analysis　of　the　local　and　the　global　thermodynamical　stability　manifests　that　the　charged　AdS　black　hole　undergoes　an　elegant　phase　transition　at　critical　point.　Of　special　interest,　critical　behaviors　of　the　black　holes　resemble　a　Van　der　Waals　liquid-gas　system.　Our　results　not　only　reveal　the　effect　of　a　global　monopole　on　thermodynamics　of　AdS　black　holes,　but　also　further　support　that　Van　der　Waals-like　behavior　of　the　black　holes　is　a　universal　phenomenon.