Two field experiments were carried out during the two summer seasons of 2007 and 2008 at Kaha Hort. Res. Station, Kaliobia Governorete. Humic acid and Azotobacter and Azospirillum as bacteria fixing nitrogen along with nitrogen levels 30, 60 and 90 kg N/fed. plus uninoculated plants were evaluated under recommended N dose 120 kg N/fed., in addition to their interaction on growth, yield and chemical composition of cucumber plants. A split plot design with three replicates was used. The results revealed that, humic acid at 0.5 % as soil application increased the vegetative growth expressed as number of leaves, plant height (cm), plant fresh and dry weight (gm) and leaf area (cm²) and increased significantly fruits/plant, plant yield (kg/fed.) Early and total yield (ton/fed.). Also, soil application of humic acid at 0.5 % had significant effect on nitrogen, phosphours and potassium. However, NO₃ in cucumber fruits was not significantly affected with humic acid. Biofertilizers (Azotobacter and Azospirillum as bacteria fixing nitrogen had a significant on all studied character in both seasons, the highest values were obtained by inoculation cucumber plants with Azotobacter and 90 kg N/fed. The interaction between humic acid and biofertilizers plus nitrogen levels had significant effect on all treats under study in both seasons. Generally, it could be concluded that, soil application of humic acid at 0.5% twice after 36 and 50 day after sowing at rate 25 ml/plant and inoculation plants with Azotobacter after 30 day after sowing at rate 25 ml/plant along with 90 kg N/fed gave the highest values of yield and NO3- concentration on cucumber fruits were within the safe levels from human