Multiwall carbon nanotubes (MWCNTs) were prepared by composite electrodeposit in a horizontal cathode mode. The electrodeposited MWCNTs have dense structure with a MWCNTs content of 22.45 % when using sulfuric nickel electrolyte, surface active solvent and brightener in a MWCNT content of 2~2.5 g/L and a voltaic density of 2.5 A/dm2. The SEM results show that the MWCNTs occupy the main volume of composite electrodepositing coating with sphere morphology for the Ni electrocrystallization. The crystallization occurs on the sunken part and the top of tubes where the Ni grains are connected each other to form a solid composite electrodeposits connecting the MWCNTs matrix and crystals. The MWCNTs content of composite electrodeposition are dominated by the MWCNTs concentration, the voltaic density and the brightener, while the connection of nickel deposition layer is dominated by the defects number and the connection of MWCNTs, and the shortest length of defect should be 1 nm at least for nucleation