Effect of bacterial inoculation and Zincapplication on yield and yield components of grain maize under water deficit stress condition were studied by experiment as split plot-factorial design with 3 replications at Mahvalat Razavi Khorasan provience, Iran in 2012. Three irrigation cycles (6, 9 and 12 days) and six levels for combination of bacteria (Pseudomonas fluorescens and P. fluorescens) and Zinc(0 and 50 kg.ha-1) were as main plots and sub plots, respectively. Results showed that simple effects of irrigation, bacteria and Zincwere significant on seed number per row, seed number per ear, 1000-seed weight, seed yield and biological yield. As irrigation cycle increased from 6 to 12 days, seed number per ear and seed yield decreased 55.4 and 57.3%, respectively. Also as Zincincreased from 0 to 50 kg.ha-1, these traits significantly increased 6.6 and 10.2%, respectively. Moreover with P. fluorescens application mentioned traits significantly increased 8.6 and 14.7%, respectively as compared with non-bacterial inoculation treatment. Zincsulphate application and PGPR decreased adverse effects of water deficit stress, but under this research conditions, irrigation cycle of 6 days and 50 kg.ha-1 Zincsulphate application and seed inoculation by Pseudomonas recomended.