In order to assess the substantial equivalence of two varieties of genetically modified rice, herbicide-tolerant Ab rice and the insect-resistant Bt rice, to the non-GM Dongjin-byeo cultivar. We analyzed the compositions and contents of the proximate, amino acids, minerals, fatty acids, vitamins, and anti-nutrients in their unpolished grains using t-test (p<0.05). A comparison of fatty acids compositions showed that the levels of stearic acid and arachidonic acid in Ab rice and those of myristic, palmitic, oleic, linoleic, and gadoleic acid in Bt rice were different significantly from the corresponding levels in Dongjin-byeo. Vitamin content did not differ between Bt and Dongjin-byeo, but the content of vitamins B1, B7, and E in Ab rice differed from that in Dongjin-byeo. Iron content in Ab and Bt rice was 2 times higher than that in Dongjin-byeo, although it was within the reference range set by Codex. The amount of the anti-nutrient trypsin inhibitor was 0.1 TIU/mg in the unpolished grain of all three rice varieties examined. Of the 47 components analyzed, 17 were significantly different among the three rice varieties; however, most of these differences were within the Codex reference range for commercial rice. Overall, it was confirmed that both Bt and Ab rice are substantially equivalent to the Dongjin-byeo and other commercial varieties of rice.