Potential risk of allergenic, toxic, and dietary risks from Genetically Modified Organism (GMO) has become critical issues. The transgenic soybean of United States has commonly been exported to countries around the world, including Indonesia. Unfortunately, there has not yet been any label given to packaging product of Genetically Modified Organism (GMO) including soybean grain sold in Indonesia. The aim of the study was to detect promoter of Cauliflower Mozaic Virus 35 S which potentially indicate the transgenic plants. Samples used in this research were 12 different brands of soybean sold in the 4 local markets. Screening of CaMV 35 S genes was done by Polymerase Chain Reaction (PCR) methods using specific primers. The result indicated that positive signals detection refers to transgenic plants in the local soybean grains with the amplification area of 123 basepairs.