Starch is synthesized from monosacharides catalyzing by different enzymes. One of the enzymes that plays a key role in starch biosynthesis is ADP - glucose pyrophosphorylase (AGPase). AGPase is composed of four subunits encoded by the two unlinked genes, Shrunken-2 (Sh2) and Brittle-2 (Bt2). Transgenic approach involving the expression of genes coding for AGPase to increase starch content is, increasingly, interested by researchers. In this article, the authors present the results on transformation of Brittle2 (Bt2) gene into inbred maize lines H20, H26, H95, and H240 using meristem of young seedling and Agrobacterium tumefaciens harboring transformation vector pCambia2300-Ubi-Bt2. The seeds from maize lines were sterilized with 70 percent alcohol and 5 percent Javen solution and cultured on MS medium. When seedling grew up to 3 - 4 cm, the coleoptiles were removed to expose the meristem. The meristem was wounded by sharp scalpel. Wounded meristem was immersed in A tumefaciens suspension for 2 hours, 4 hours and 16 hours (over night) at room temperature. The transformed plantlets were selected on the medium containing 200 mgll kanamycin. The presence of Bt2 gene in transformed TO plants was shown by PCR and Southern blot analyses. The percentage of transformed plant were varied among the studied maize lines and the values were 2.44, 3.67, 5.91 and 7.55 percent for H240, H20, H26 and H95, respectively. After Southern analysis, 17 transformed plants possessed Bt2 gene were obtained, among them 10 from H95 line, 6 from H26 line, and 1 from H240 line. The results also indicated that 16 h (over night) treatment of the meristem of young seedling with A. tumefaciens carrying trans gene was the best for genetic transformation of maize's meristem. The results of this study will contribute, considerably, to the genetic transformation of the genes involving in starch biosynthesis in maize.