The performance of SBA-16 catalysts toward the degradation of two kinds of polyethylenes, high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE), was evaluated by using a thermogravimetric analyzer and batch reactor. The effect of the acidity of SBA-16 upon degradation efficiency was investigated. Quantitative analyses of the products were conducted by GC/MS and GC. The Al-SBA-16 led to a higher catalytic conversion than SBA-16. Hydrocarbons (C7-C10) were mainly produced by Al-SBA-16, whereas a much broader distribution of oil products (C7-C14) was obtained by SBA-16. The Al-SBA-16 also showed high catalytic stability. The results of this study suggest that Al-SBA-16 has a high potential as a catalyst for degradation of waste plastics.