Hydrocarbons were analyzed in irradiated beef, pork, dried and seasoned beef, dried anchovy, dried squid, dried shrimp, and fish paste to determine whether the hydrocarbons can be used as markers for detecting post-irradiation of the imported meat and fish products. The samples were irradiated at 0.5, 1, 3, and 6 kGy. Fat was extracted with hexane, and hydrocarbons were separated from the fat through Florisil column. The hydrocarbons were analyzed with GC. Hydrocarbons 15:0, 16:1, 17:1, 16:2, 17:2, and 16:3 in beef and pork, 17:1, 16:2, and 17:2 in dried and seasoned beef, 16:2 in dried anchovy, 16:1 and 17:1 in dried squid, 16:1, 17:1, and 16:2 in dried shrimp, and 16:1, 16:2, and 16:3 in fish paste were detected in the irradiated samples, but not in the unirradiated, so that the hydrocarbons may be used as makers for detecting post-irradiation of each item.