Iron is an essential mineral found in every cell of the human body to make the oxygen-carrying proteins hemoglobin and myoglobin. More than 2 billion people face Fe deficiency. Rice can be a potentially valuable source to supplement that mineral since it is staple food for two-thirds of the world’s population. To bring the nutritional level of the milled product up to that of the whole grain (brown), rice should be enriched with thiamin, niacin and iron. Also iron has important role that absorption from the photosynthetic cells proceeds, chlorophyll synthesis and the growth process of the plant. Orthologous genes, which are homologous genes that diverged after a speciation event, generally maintain a similar function in different species. We applied a McDonald-Kreitman Test (MKT) to examine more than 10,000 orthologous genes between rice (Oryza sativa) and Brachypodium (outgroup) based on different phenotypic groups. This analysis was undertaken to find fast evolutionary genes in rice iron uptake. Three groups were separated based on the phenotype and each group was examined with the outgroup for MKT. Fast evolutionary genes that have a positive selection with FDR ≤ 0.05 were detected at each groups. Annotation of these genes were conducted and the predicted functions were also discussed here. And also, the association study between the candidate gene related to iron uptake phenotype was performed. These results support that using this orthologous based method, we may find some important candidate genes underlying the ion uptake in rice.