A series of aryl-substituted N-hydroxyphthalimides ( X-NHPI) containing both electron-withdrawing groups and electron-donating groups have been synthesized. The effect of substitution in the aromatic ring of N-hydroxyphthalimide on catalytic activity in cyclohexane oxidation has been tested. The results showed that the electron-withdrawing groups enhance the catalytic activity of the NHPI, the electronwithdrawing ability was stronger. On the other hand, the electron-donating groups decrease the catalytic activity of the NHPI.