For the selection of the most suitable rice varieties for processing of germinated brown rice products in Mekong Delta, six varieties commonly planted in the Mekong Delta (Jasmine85, OM4900, OM2517, CLN, MBD, IR50404) were selected for study. In order to do that protein, starch, amylose, total polyphenol and GABA content were determined during 24 hours of the germination of the brown rice in aerobic and anaerobic conditions. GABA was biosynthesized with the highest levels in four varieties such as Jasmine85, IR50404, MBD and CLN in anaerobic germination conditions as 37.56 mg/100g, 35.39 mg/100g, 30.32 mg/100g and 24.65 mg/100g respectively. During the germination, both polyphenol and GABA showed a significant increase as 1.15 - 4.58 times and 1.56 - 3.34 times respectively. The high level of initial GABA content in the material may relate to the highest increase of this component during the germination. There were no relationship between initial protein and starch content to the capacity of increase of GABA and polyphenol compounds during the germination. However, high initial amylose content related to fast germination to get maximum GABA content but it is not related directly to GABA biosynthesis capacity. In addition, the rice variety which was high ability of making the increase of high protein content during germination seems to be related to the ability to biosynthesize GABA and polyphenol compounds. The results indicate that 3 varieties as Jasmine85, IR50404 and MBD can be used as materials for germinated brown rice production in Mekong Delta.