T HE MOST efficient phosphate solubilizing bacterial strain was isolated from rhizosphere of healthy rice plants and identified as Enterobacter cloacae (B1) based on morphological and biochemical characteristics and 16S r DNA. The optimum phosphate solubilization conditions for pH, temperature and incubation period were obtained at 8, 30 °C and 3 days, respectively. Accordingly, Enterobacter cloacae (B1) was evaluated under field conditions through its impact on growth and yield characteristics of wheat (Triticumaestivum L.) cultivar Masr 1 in comparison with chemical fertilizers (phosphoric acid,calcium super phosphate and NPK). Results of this study showed that, Enterobacter cloacae (B1) effectively increased growth characteristics including plant height (cm) (9.96 %), fresh weight (g/plant) (86.78 %), dry weight (g/plant) (58.36 %) and flag leaf area (cm 2 ) (53.68 %) and physiological characteristics including chlorophyll pigments content, chl. a, b and total (µg/cm 2 ) (31.91 %, 35.81 % and 33.33 %, respectively)as well as yield characteristics such as spike length(cm) (13.14 %), spikelets number (13.58 %), grains number/spike (23.16 %), 1000 kernels weight (g) (6.49 %), spike weight(g) (29.37 %), biological weight(g/m 2 ) (55.92 %) and grains weight(g/m 2 ) (41.18 %) in comparison with control treatment.