Diamond deposition by muti-cathode DC PACVD has been investigated. Five cathodes were independently connected to their own DC power supplies. The voltage and current of each cathods were varied up to 700 V and 3.5 A, respectively. The plasma formation and the diamond deposition behaviour on a substrate of 3 inch in diameter were investigated by optical emission spectroscopy, SEM and Raman spectroscopy. The plasma formed by five cathodes was non-uniform, which was depended on the geometry of cathods array. The growth rate and the quality of diamond film were closely related to the spatial distribution of the plasma.