The oxidation of propionaldehyde initialized by thermal reaction, Co-type resin catalyst, and Mn-type resin catalysts was carried out. The results revealed that the yield of perpropionic acid was significantly increased by using Co- or Mn-type resin as catalyst instead of thermal initialization. A faster reaction rate was found by using Co-type resin as catalyst. However, a higher selectivity of perpropionic acid was obtained by using Mn-type resin as catalyst. The following rate equations were obtained when the propionaldehyde concentration and catalyst loading increased from 1.39 to 2.78 M and from 2 to 4g/L, respectively, at 283 K : R(c) = 6.45 x 10(-3) [RCHO(b)]1.41 [s-Co3+]0.56, for Co-type resin; R(c) = 4.98 x 10(-3)[RCHO(b)]1.59[s-Mn3+]0.41, for Mn-type resin; R(c) = 1.08 x 10(-4)[RCHO(b)]1.76, for thermal reaction. RCHO, s-Co3+, and s-Mn3+ indicate propionaldehyde, Co-type resin, and Mn-type resin, respectively. The activation energies were found to be 75.8, 60.9, and 44.8 kJ/mol using thermal, Co- and Mn-type resin catalysts, respectively. Mixing of Co- and Mn-type resins could not improve the selectivity of perpropionic acid.