A heterogenized homogeneous catalyst with a bias active site distribution was investigated. The polymer supports of the catalyst with a bias active site distribution were designed and prepared by means of controlling the sulfonation reaction of the polystyrene resin. The results showed that the reaction rate of aldehyde oxidation increased with an increase of the film thickness with a bias active site of the catalyst particle and reached a maxima when the film thickness with a bias active site was equal to the catalytically effective thickness. The turnover number, however, decreased sharply with an increase of the film thickness with a bias active site of the particle. The results also showed that the reaction rate and the turnover number of aldehyde oxidation initiated by the heterogenized homogeneous catalyst with a bias active site distribution was larger and 100 times higher, respectively, than that of using a Co-type catalyst supported by the commercial resin. The behavior of the heterogenized homogeneous catalyst was much more improved when using the catalyst with a bias active site distribution. © 1990, American Chemical Society. All rights reserved.