Abstract: In order to improve the effect of copper-plating of natural flake graphite powders,the pretreatment process of natural flake graphite powders was carried out first.Then,electroless copper-plating on graphite was proceeded.The influences of solution temperature,main salt cocentration,reductant addition and loading capacity on deposition reaction were discussed and the processing parameters were also optimized.Finally,copper-coated graphite powders was passivated and characterized.The results show that the optimal parameters were as follows:plating solution temperature 50.0 ℃,copper sulfate mass fraction in plating solution 20.0 g·L-1,formaldehyde addition 25.0 mL·L-1 and loading capacity 5.0-6.0 g·L-1.Under the condition,a better stability and high deposition rate could be achieved.Graphite powders coated by copper totally with smooth-bright visualization could be obtained.The oxidation resistance of copper coating was greatly improved by using 1,2,3-benzotrialole alcohol solution as passivating agent.