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．
