The present work was performed to study the effect of inoculation with Azospirillum brasilense N040 on the protein pattern of shoots and roots of seedlings of two barley cultivars (Giza 123 and Giza 2000) which are known by their different tolerance to salt stress. A greenhouse experiment was conducted to evaluate the effect of inoculation on the molecular masses of protein contents of both studied barley cultivars cultivated under 350 mM NaCI through the determination of SDS-PAGE protein profile of shoots and roots. Results showed that the salt stress, bacterial inoculation and the interaction between them resulted in noticed changes in the protein patterns of shoot and root in all treatments.