BiFe1-xCoxO3　crystals　(x=0,　0.01,　0.03,　0.05,　0.07,　0.09,　0.11)　were　prepared　by　the　optical　floating　zone　method.　The　growth　conditions,　such　as　growth　temperature,　rotational　speed　and　growth　rate　were　studied.　BiFe1-xCoxO3　crystals　with　a　diameter　of　(8-12)　mm　and　a　length　of　(60-120)　mm　have　been　obtained　by　optimizing　growth　conditions.　Hysteresis　loop　test　showed　the　highest　saturation　magnetization　was　5.5　emu/g　at　x=0.11.　Dielectric　temperature　spectrum　revealed　the　lowest　Ne´el　temperature　reached　320°C　at　x=0.05.　The　antiferromagnetism　improved　at　room　temperature　and　dielectric　constant　increased　apparently　as　the　proportion　of　Co-doped　increasing.