Abstract: 4-Methylbenzophenone and benzophenone in plastic food packaging material were determined by GC hyphenated with MS. Sample was treated with methylbenzene by microwave assisted extraction. An aliquot of the extract was taken for GC-MS determination. Under the selected working conditions of the instrument, 4-methylbenzophenone and benzophenone were successfully separated. The characteristic ions with m/z 119.0 and 196.1 were selected for quantitative analysis of 4-methylbenzophenone and the ions with m/z 77.0 and 105.0 for benzophenone. Values of detection limits (3S/N) found were 2.0×10-5mg·kg-1. Tests for recovery were made by standard addition method; the results of recovery of 4-methylbenzophenone and benzophenone obtained were 94.3% and 95.0%, with values of RSD′s (n=6) of 3.4% and 2.8% respectively.