Bismuth　ferrite　crystal　is　synthesized　by　hydrothermal　method.　The　effect　of　hydrothermal　temperature,　KOH　concentration,　supersaturation,　cooling　rate,　and　compactedness　on　the　crystal　phase　and　the　morphology　of　product　were　investigated.　The　results　indicated　that　BiFeO3　microcrystalline　with　good　quality　could　been　synthesized　at　140-240　°C　with　KOH　concentration　of　4-14　mol　L-1.　In　addition,　it　is　favorable　for　improving　the　crystal　quality　to　reduce　the　supersaturation　and　decrease　the　cooling　rate.　With　the　increasing　of　the　compactedness,　surface　holes　and　cracks　of　the　as-grown　crystals　would　be　reduced.　The　optimization　of　hydrothermal　condition　provides　guidance　to　grow　BiFeO3　crystal　with　a　large　size　and　high　quality　for　practical　application.　©　2015　Elsevier　B.V.　All　rights　reserved.