The current work aimed to elucidate the effect of N mineral fertilization rates in combination with N bio-fertilizer source and its rate on barley yield (Hordeum vulgare L.) var. Giza 2000 and its components in sandy soil. Afield experiment was conducted at Kantra Shark, north Sinai Governorate during 2017/2018 winter season using randomized complete block design with split split plot arrangements replicated three times. The main plots   assigned to four mineral - N rates (0.0, 50, 75 and 100 kg N fed^-1) as ammonium sulphate (205g N kg^-1). The sub plots occupied by two commercial bio-fertilizer sources, Cyrialine and Microbine. The sub-sub plots dedicated to three bio-fertilizer rates (0.0,400,600 and 800 g fed^-1). The results appeared that barley grain, straw and biological yields, harvest index(HI), grains protein content (%), N, P , K-uptake (kg fed^-1) by grains or straw , total uptake (grains + straw)  ,  agronomical and recovery (P and K) use efficiencies increased significantly with increasing N-fertilizer rate up to 100 kg fed-¹.Agronomical,  recovery nitrogen use efficiencies and physiological (N,P and K ) use efficiencies decreased significantly with increasing N-fertilizer rate. Cyrialine was superior to Microbine in its beneficial effect on most abovementioned traits. All studdedvegetative characters as well as chemical composition, nutrient uptake and nutrient use efficiency increased significantly with increasing bio-fertilizer rate. Generally, although the crop responsed to mineral N rates up to 100kg N fed^-1 under the studied soil (sandy), the combination application with bio-fertilizers was the best for all studied parameters and can save approximately 25 % of mineral N fertilizer at least as well as help in reducing mineral fertilizer pollution in growth media.