Six dendritic PAMAMSA-Mn (II) complexes were synthesized and were well characterized. The oxidation of cyclohexene under 1 atmospheric pressure of molecular oxygen in the absence of any solvent with the synthesized complexes was employed to value their catalytic properties. It was shown that all the dendritic complexes with different generation numbers (G) exhibit promising catalytic activities for the oxidation. Under the mild condition, all the oxidations give 7-oxabicyclo[4,1,0]heptane 1, 2-cyclohexen-2-ol 2, 2-cyclohexen-2-one 3 and 7-oxabicyclo [4,1,0]heptan-2-one 4 as the major products. The factors that affect the oxidations were also well investigated under identical conditions. (C) 2004 Elsevier B.V. All rights reserved.