Glycolysis temperature, glycolysis time, and amount of catalyst are important factors affecting the glycolysis of recycled poly(ethylene terephthalate) (PET) flakes. A 2(3) factorial experimental design is applied to study the main, two-factor interaction, and three-factor interaction effects of glycolysis temperature, glycolysis time, and amount of catalyst on the glycolysis of recycled PET flakes. In this study cobalt acetate is used as the glycolysis catalyst. The sequence of the main effects on the glycolysis conversion of the recycled PET flakes in ascending order is glycolysis time < glycolysis temperature < amount of catalyst. The sequence of the two-factor interaction effects on the glycolysis conversion of the recycled PET flakes in ascending order is glycolysis temperature versus the glycolysis time ( glycolysis time versus the amount of catalyst ( glycolysis temperature versus the amount of catalyst. The three-factor interaction effect is significantly related to the glycolysis conversion of the recycled PET flakes.