Recently medicinal plants fatty acids involve in reduce of vascular and coronary diseases of human. There are many factors that affect on secondary metabolite and growth of medicinal plants. Linseed is one of the most important sources of unsaturated fatty acid (F.A.), notably polyunsaturated F.A. of N-3 series and conjugated linoleic acid. In this study the effect of different levels of Nitrogen and irrigation regimes was to investigate on linseed fatty acids, growth and yield. The irrigation regimes were including; 0, 20, 60 mm (regulated by Tensiometer) and Nitrogen fertilization levels 0, 50,150 and 250 kg Nha −1 . The rate of plant height, fruit Numbers, branch numbers, 1000 seeds weight, yield per ha were determined in the end of experiment. Also oil percent in seeds and fatty acids quantity (Palmitic acid, Stearic acid, Oleic acid, Linoleic acid) were measured in ripe seeds. Results show, fruit Numbers, plants height, branch numbers and yield per hectare were significantly increased and seed oil percent, and fatty acid quantity were significantly decreased by application of high Nitrogen and irrigation. Within each irrigation regimes fatty acid amount was not significantly changed by Nitrogen supplementation.
