Nitrogenous fertilizer as the most important element of the plant nutrition in the agricultural ecosystems has vital effect on the physiologic processes and different yields of the genotyps and the plant varieties. Fennel ( Foeniculum vulgare ) is one of the most important and the oldest medicinal plants in Iran and has been effective in the treatment of many of diseases. In order to determine the most appropriate bulk and N level for the yeild acquiring, yeild elements, kernel essential oil percent and essential oil in the shoot of Fennel, an experiment was conducted in the research field of Isfahan University of technology located at Najaf Abad, Lavark as split plot plan and in the random completed blocks with three replications. Main plots were allocated amount of N fertilizer include 0-40-80-120 160 kg/ha and the subordinate plots were allocated to four bulks of Fennel ( Isfahan , Tehran , Yazd , European11486). The cultivation was accomplished in March 10 in the rows with 50cm distance through hand spreader and the bushed distance was designed on the row with 20cm. distance results showed that, Nitrogenous fertilizer amounts hadn't significant effect on the day number to 50 percent sprouting, 50 percent umbeling, 50 100 percent flowering, umbelliferous subbranch number, branch height, scale fern number in umbel, thousand-kernel weight, kernel essential oil percent and kernel dry matter percent. The bulk mutual effect and N fertilizer on the day number to first flower appearance, umbelliferous stalk number, the bush height, tiller number in the bush, umbel number in the bush, scale fern number in umbel, kernel number in scale fern, seed long, thousand kernel weight, shoot essential oil percent, kernel protein percent, kernel ash percent, kernel dry matter percent, harvest index and dry matter yield were significant. The bulks response was different in the most of evaluating attributes which is because of the difference in the bulks genetic indentity. The most kernel yield per bush and per hectare and dorema essential oil percent were achived in 160 N kg/ha, the most kernel essential oil percent was seen in 40 160 kg, the most kernel thousand weight was achived in 40 120 kg, the most harvest index was achived in 40 160 kg, Keywords: Medicinal plants, Fennel, essential oil, protein, kernel yield, Nitrogenous fertilizer, Bulk
