To investigate the responses growth indices of corn (Zea mays L. cv. SC 604) to using plant growth promoting rhizobacteria (PGPR) and phosphate solubilizing microorganisms (PSM) and rhizobacteria, a field experiment was conducted during 2008. The study was arranged in split plot experiment based on randomized complete block design with three replications. Three levels of manures, consisted of 20 Mg.ha-1 farmyard manure, 15 Mg.ha-1 green manure and check or without any manures assigned to main plots and eight levels of fertilizer combinations (consisted of 1-NPK or recommended fertilizer application; 2-NPK+PSM+PGPR; 3-NP50%K+PSM +PGPR; 4-N50%PK+PSM+ PGPR; 5-N50%P50%K+PSM+ PGPR; 6-PK+PGPR; 7-NK+PSM and 8-PSM+ PGPR) to sub plots. Results showed that the maximum dry matter (13/2 g.m-2), leaf area index (3/8) and crop growth rate (34/5 g.m-2.day-1) were, produced by using both farmyard manure and application of NPK plus biofertilizers. Application of green manure and biofertilizer significantly increased dry matter by 11% compared to control. Meanwhile, farmyard manure and green manure application markedly increased the leaf area index by 17 and 10%, respectively. NPK treatment in farmyard manure plots and inoculation of PGPR and PSM significantly increased crop growth rate in corn plants compared to green manure and control plots. However, inoculation of biofertilizer and reducing P application by 50% did not significant influence growth indices such as total dry matter accumulation, leaf area index, and crop growth rate significantly. In conclusion, it seems that biofertilizers could be recommended as an effective option to reduce phosphate chemical fertilizers, improve the growth indices of corn plants, which ultimately result in grain yield increase