The　pyrolysis　of　Chlorella　sp.　was　carried　out　in　a　microwave　oven　with　char　as　microwave　reception　enhancer.　The　results　indicated　that　the　maximum　bio-oil　yield　of　28.6%　was　achieved　under　the　microwave　power　of　750W.　The　bio-oil　properties　were　characterized　with　elemental,　GC-MS,　GPC,　FTIR,　and　thermogravimetric　analysis.　The　algal　bio-oil　had　a　density　of　0.98　kg/L,　a　viscosity　of　61.2　cSt,　and　a　higher　heating　value　(HHV)　of　30.7　MJ/kg.　The　GC-MS　results　showed　that　the　bio-oils　were　mainly　composed　of　aliphatic　hydrocarbons,　aromatic　hydrocarbons,　phenols,　long　chain　fatty　acids　and　nitrogenated　compounds,　among　which　aliphatic　and　aromatic　hydrocarbons　(account　for　22.18%　of　the　total　GC-MS　spectrum　area)　are　highly　desirable　compounds　as　those　in　crude　oil,　gasoline　and　diesel.　The　results　in　this　study　indicate　that　fast　growing　algae　are　a　promising　source　of　feedstock　for　advanced　renewable　fuel　production　via　microwave-assisted　pyrolysis　(MAP).　(C)　2011　Elsevier　Ltd.　All　rights　reserved.