Sonoelectrodeposition technique has been used to prepare bioactive brushite coatings on carbon/carbon composites. The effects of current density on the structures and morphology of the bioactive brushite coatings were also investigated. It is found that the coatings with plate like (021), granular like (111), and flower like(220)morphology can be fabricated by using different current densities respectively. The results show that the sizes of as deposited particles decrease with increasing current density. In addition, the mechanism of the variation of their microstructures was also discussed.