Basil is a medicinal plant from the mint genus that is used in the pharmaceutical industry. A study was conducted to investigate the effect of biofertilizers and nitrogen on some physiological traits and yield of basil essential oil in the research greenhouse of the Faculty of Agriculture, University of Tabriz in 2010. A study was conducted to investigate the effect of biofertilizers and nitrogen on some physiological traits and yield of basil essential oil in the research greenhouse of the Faculty of Agriculture, University of Tabriz in 2010. Control (T1), chemical fertilizer (T2), biofertilizer (T3) and combined treatment of chemical and biological fertilizer and two native basil stands: Tabriz (V1) and Mazandaran (V2) were tested. The experimental design was factorial in the form of randomized complete blocks with 9 replications. Morphological traits (plant height, stem diameter, number of lateral branches per plant, number of leaves per plant, lateral branch length), recording of phenological stages (emergence to flowering), physiological traits (leaf area, stomata density, nitrogen use efficiency, chlorophyll index The percentage and yield of essential oil, the percentage of nitrogen in the leaves, the amount of chlorophyll in the leaves, the fresh and dry weight of the shoots, the dry weight of the leaves and the ratio of crown to root) were evaluated. The results showed that stem diameter, plant height, number of branches were affected by biofertilizer and chemical treatments. The number of leaves and flower length were affected by biofertilizer and chemical treatments, respectively. The native population of Mazandaran was superior to the native population of Tabriz in stem diameter and plant height. The composition of biofertilizers and chemical fertilizers had an effect on the duration of vegetative growth. Flowering was delayed under this treatment but biofertilizer treatment reduced the vegetative growth period. Also, flowering in the native land of Tabriz was done later than the land of Mazandaran. Biofertilizer and its combination with chemical fertilizer had no significant effect on stomatal density, but on leaf area, leaf dry weight, dry and wet weight of shoot, crown to root ratio, percentage and yield of essential oil in both folds, chlorophyll a and b, Nitrogen percentage had a significant effect. These fertilizer treatments had no effect on chlorophyll index. The second fold in leaf area, chlorophyll index, chlorophyll a and b levels, nitrogen content and nitrogen use efficiency were better than the first fold.