Abstract: The colonization potential of plant growth promoting bacterial strains (Ochrobactrum intermedium, Bacillus cereus and Brevibacterium sp.) on Triticum aestivum and Helianthus annuus roots. The roots of Triticum aestivum were heavy colonized with Ochrobactrum intermedium and Bacillus cereus as compared to Brevibacterium. Ochrobactrum intermedium mainly colonized the rhizoplane while Bacillus cereus was present both on the rhizoplane and near the root zone. Ochrobactrum intermedium and Bacillus cereus were found to be present both on the rhizoplane as well as near root zones of both crops used (Triticum aestivum and Helianthus annuus) while Brevibacterium was found in the form of groups in the rhizosphere of Helianthus annuus roots. From the results of both crops it was observed that the number of Ochrobactrum intermedium cells were more where some root exudates seen.