The effects of metal particle size on catalytic activities of Cu/SBA-15 with different Cu content were investigated for high selectivity of cyclohexane dehydrogenation. Overall, the smaller Cu nanoparticles exhibit higher hydrogen evolution rate or lower active energy barrier. But, even when the smaller CuO nanoparticles have formed on the catalyst with lower Cu content during the calcination, they would be more prone to sinter after reduction. An appropriate Cu content could lead to form amounts of stable and small Cu nanoparticles after high-temperature treatment with the space limitation by ordered channels of SBA-15.