 Plant growth promoting rhizobacteria, PGPR, can be selected by screening bacteria for achieving the most promising isolates having suitable colonization and PGPR traits. This process should include selecting bacteria for achieving the highest colonization rates and PGPR traits. Additionally, it is important to study all the isolated bacteria in an economical way and select the best bacteria in terms of PGPR traits and high colonization rate. A simple screening method to detect endophytic and rhizosphere bacteria, isolated from the plants in rotation with rice, for rice PGPR agents based on a root colonization bioassay and a PGPR trait is characterized. This article was authored by Hassan Edassami, Hossein Ali Alakani and Hossein Merced Hosseini.