Thermolysis of Cu(NO₃)₂3H₂O impregnated activated carbon fiber(ACF) was studies by means of XRD analysis to obtain Cu-impregnated ACF. Cu(NO₃)₂3H₂O was converted into Cu₂O around 230℃. The Cu₂O was reduced to Cu at 400℃, resulting in ACF-C(Cu). Some Cu particles have a tendency to agg regate through the heat treatment, resulting in the ununiform distribution in ACF.