Two field experiments were conducted at the farm of Tag EL-EZZ Res station, Dakahlia Governorate, during winter seasons of 2002/2003 and 2003/2004 The work aimed to study the effect of three nitrogen sources and their mixtures yield, some seed characters and mineral concentrations in some flax genotypes (Sakha 1 & Sakha 2 varieties and strains of 2419/1 & 413/1/3/2). The nitrogen sources were used are: urea (46% N), ammonium nitrate (33% N) and ammonium sulphate (20.5% N) with the recommended dose (45 kg N fed‘1). The obtained results can be summarized in the following: 1- The data showed that, there were highly significant differences between flax genotypes for the studied parameters in both seasons. 2- Sakha 1 variety surpassed Sakha 2 and the strains of 2419/1 and 413/1/3/2 plant height, technical length, straw yield/plant, straw yield/fed. and fiber yield in both seasons. 3- Sakha 2 surpassed Sakha 1, 2419/1 and 413/1/3/2 for seed index and seed yield/fed. in both seasons, as well as macro and micronutrients concentration while strain 2419/1 surpassed other strains and species for No. capsule and seed yield/plant in both seasons. 4- Using ammonium nitrate + ammonium sulphate significantly increased all studied parameters as yield and seed characters, as well as macro and micronutrients concentration in both studied seasons. 5- It is noticed that, the interactions effect between all treatments on all studied parameters were heighly significant in both seasons, of present work.