Pots experiments were conducted on corn plants (Zea mays, L.), Trihybrid 302, at the experimental greenhouse of the Agriculture Faculty (Saba-Basha), Alexandria University, Egypt to evaluate the effect of rock phosphate, some nano-herbicides particlesand phosphate solubilizing bacteria on growth and chemical composition of corn plants grows in calcareous soil. The experiment was designed as spilt -spilt plot design with four replicates. Each replicate contained 8 treatments as follows: main plot as rock phosphate (0, 50 and 100), subplot as herbicides (Control, herbicide, nano-herbicide), sub-sub plot phosphate solubilizing bacteria (Uninoculated, Bacillus megaterium). Results indicated that, the interaction with rock phosphate at a rate 100%  of the recomonded dose and nano-herbicides in the case of plants inoculated with B. megaterium bacteria recorded the maximum mean values of vegetative growth of maize (plant height, total chlorophyll (SPAD), shoot fresh weight, shoot dry weight, leaf area index, as compared of control plants which gave the minimum mean values of these characters. Also, rock phosphate at 100% rate, nano-herbicides and bacteria gave the highest mean values of root fresh and dry weight, as compared with control. Moreover, rock phosphate at 100% rate, nano-herbicides and bacteria gave the highest mean values of N, P, K percentages in shoot, as compared with control.