This study is part of out comes from a projects financed by researching unit of MansouraUniversity. Spacing uniformity, seed volumetric rate and irregular depth of seeds in soil for wheat and sorghum are the most common characteristics used to evaluate the injection planter performance. The injection mechanisms speed, level of air pressure, the shape and the size of orifice head and the seed bulk density may all influence seed singulation and placement the seeds. The theoretical studies were carried out on the seed speeds during came out from the injection device nozzle until moment of the seed calmed in the soil. The amount of volumetric flow rate "seed/s" is direct proportional to the injection pressure and also to the seeds density (the flow rate of sorghum largest than the wheat seeds) and inversely proportion to the orifice diameters. Also the seed spacing in row increased with the increase of planting speed and pressure. The statically analysis confirm that the seeding speeds (m/s) have a major effect on the seed miss and double index.