A field experiments were carried out at El-Wanysa village, Itsa district, El-Fayoum Governorate during two successive seasons of 2007 and 2008. The current work aimed to study the effect of both organic (compost) and inorganic nitrogen (ammonium sulphate) fertilizers and their combination on maize growth, yield and its components as well as grain contents of protein, oil and some nutrients The obtained results could be summarized into: -    Concerning the nitrogen sources, it seems that the combined treatment of N-organic +N-mineral gave the greatest values for yield and its components, NPK concentration and it's uptake by maize plant. Also, the values of chlorophyll a, b, total chlorophyll content,  ear length, ear diameter, ear weight, grain weight/ear, number of row/ear, number of grain/row, 100-grain weight and grain yield (ardab/fed.) were significantly increased by increasing nitrogen levels. -    Increasing nitrogen fertilizer rates up to 120 kg N/fed. significantly increased nitrogen concentration and its uptake as well as protein content. -    Phosphorus concentration and its uptake were significantly increased by applying 120 kg N/fed. -    Oil percentage, oil yield and grain total carbohydrate percentage increased significantly as N level was increased up to 120 kg N/fed. -    Concerning the interaction effect between nitrogen sources and it's levels, it could be noticed that the ammonium sulphate + compost mixture treatment at 120 kg N/fed. was the better treatment due to its positive effect on grain yield and its components. -    It may be concluded that the application of compost combined with inorganic nitrogen was more effective on yield and its components of maize plant as compared to the addition of mineral nitrogen or compost alone. This may be the positive effect of organic manure on the physico-chemical properties, besides it attains a pronounced content of essential nutrients, especially micronutrients. -    In general using organic manure improved yield and saved considerable amount of required mineral fertilizers which may decreased the chemical pollution of environment.