It aims to study the determination of 2,4-diaminotoluene in composite food packaging film bags by gas chromatography-mass spectrometry (GC-MS), and investigate the concentration of 2,4-diaminotoluene in food packages in Chaozhou. Samples were immersed with water at 100 ℃, then the immersion liquid was extracted with methylbenzene and derivatized with trifluoro-acetic anhydride. Finally, its derivative was analyzed by GC-MS. There was linear relation between the peak area of the quantitative ion and the concentration of 2,4-diaminotoluene in range of 1~100 μg/L. The limit of detection was 0.2 μg/L and the correlation coefficient was up to 0.9994. Recovery was 89.0%~95.2%, RSD was 1.80%~4.70%. The investigation results indicated that 5 of the 30 samples contained 1.1~6.4 μg/L 2,4-diaminotoluene, and one of them reached 6.4 μg/L, exceeding the standard limit (less than 4 μg/L). The qualified rate of the 30 samples reached 96.7 %. That indicated the content of 2,4-diaminotoluene in food packaging material was basically good. In conclusion, the gas chromatography-mass spectrometry (GC-MS) method is featured by low limit of detection, high recovery rate, and accurate and reliable results.