Silica-supported copper catalysts were prepared by the ion-exchange method. Copper was loaded on silica as copper tetramine ion-exchanged to proton of silanol group and copper hydroxide entrapped in the fine pores of silica. Copper dispersion decreased with copper loading. The selectivity to cyclohexanone increased with copper loading, accompanying by decrease in the selectivity to cyclohexene. The selectivity to phenol increased sharply with high loading of copper. The decrease in the selectivity to cyclohexene with copper loading was interpreted by the masking of weak acid site, while the increase in the selectivity to phenol by existence of large particles to enhance multiple dehydrogenation of cyclohexane ring.