Abstract: A method of determination of residual amounts of the fresh-keeping agent-Imazalil in orange and its products by GC-MS was proposed. Samples were ectracted with a mixed solvent of ethyl acetate and n-hexane (1+1). The extract obtained was purified to remove the macromolecular impurities by gel permeation chromatography. The eluates were taken for separation by GC and the content of Imazalil was determined by MS under select ion monitoring mode. Values of detection limits (3S/N) of the method found was 0.02 mg·kg-1, and lower limit of determination (10S/N) found was 0.05 mg·kg-1. Tests for recovery were made by addition of standard solution at 3 different concentration levels, values of recovery found were in the range of 79.0%-92.1% with RSD′s (n=6) less than 10%.