Celery (Apium graveolens L.), a biennial plant of the Apiaceae family. It is frequently used as a vegetable, spice, and natural medicine in Egypt. The objective of this work was to study the effect of three nitrogenous concentration solutions on vegetative, yield and chemical characters of three celery cultivars under floating hydroponic system. Two experiments were conducted in a completely randomized block design with a split-plot arrangement of treatments at three replicationsduring the winter seasons of 2014 and 2015 in hydroponic floating system in a polyethylene greenhouse. The nutrient solutions with three N-level (90,180 and 270 ppm) were assigned to main plots and three celery hybrids cultivars (Utah, Presedent and Montery) were allocated to subplots. The results indicated that the intermediate nitrogen level (180 mg. L^-1) brought about the highest significant mean values of plant height, number of leaves/ plant, plant fresh weight and total yield kg.m^-2. Data, also, expressed that the lowest nitrogenous levels (90 mg. l^-1); gave rise of the highest significant mean values for TSS and pH characters, in both seasons. On the other hand, the three nitrogenous levels didn't differ, significantly, in their effects on V.C, total phenols and acidity characters of celery plants, during both seasons. Also, data showed that "Utah" variety showed the highest significant values for vegetative and total yield characters compared with the other tested hybrids.