Two field experiments were carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Agricultural Research Center, Egypt, during the two growing summer seasons of 2010 and 2011. The main objective of this study was to evaluate the effect of compost rates, humic acid treatments and nitrogen fertilizer rates on growth, grain yieldand its components of maize cultivar yellow single cross 166. Each rate of compost was performed in separate experiment. Every experiment of compost rates was carried out in split plot design with four replications. The main plots were occupied with humic acid treatments. The sub-plots were assigned to nitrogen fertilizer rates. The obvious results of this investigation can be summarized as follows: Adding 30 m³ compost/fed recorded the highest values of growth traits, grain yield and its attributes in both seasons and their combined. Moreover, applying 15 m³ compost/fed came in the second rank in both seasons and their combined. The lowest values of these characters were obtained by control treatment (without compost) in both seasons and their combined Soaking seeds before planting in humic acid plus foliar spraying plants with humic acid enhanced maize growth, subsequently produced the highest means grain yield and its attributes in both seasons and their combined. It was followed by soaking seeds before planting in humic acid or foliar spraying plants with humic acid in both seasons and their combined. There were substantial differences in all studied characters among various studied nitrogen fertilizer rates inboth seasons and their combined. Fertilizing maize plants with 120 kg N/fed produced the highest values of these characters inboth seasons and their combined. However, using 60 kg N/fed was accompanied with the least values of grain yield and its attributes characters inboth seasons and their combined, as well as there are many significant effect of the interactions among studied factors on studied characters. Generally, it can be concluded that organic fertilizing maize plants hybrid S.C. 166 with 30 m3 compost/fed and soaking seeds plus foliar spraying plants with humic acid at the rate of 1000 ppm in addition mineral fertilizing with 120 or 90 kg N/fed in order to maximizing its growth and productivity under the environmental conditions of Gemmeiza district, El-Gharbia Governorate.