Abstract: Diamond films had been grown by microwave plasma assisted CVD using acetone as C source diluted in hydrogen with co-doping by using dimethyl disulfide and boron trioxide.The growth rate and resistivity of deposited films were all reduced with increasing sulfur additions.Under the same levels of S additions,conductive activation energy of films were decreased with the increasing of B additions,which were between 0.26~0.33eV.It is proved that the limited amounts of boron facilitated sulfur incorporation into diamond.The B-S co-doped diamond films were much more perfectl with higher quality than the S-doped diamond film.Hall effect measurements revealed that the S and B/S doped diamond films exhibited n-type,which carrier concentration and Hall mobility were among ~10¹⁶-10¹⁸/cm³,7~80cm²V^-1s^-1 respectively.Compared with S-doping diamond film,B/S co-doping diamond film had higher Hall mobility.