This experiment was performed in 2004 to evaluate the effects of different rates and methods of nitrogen fertilizer application on morphological characteristics and yield of Melissa officinal is L under field conditions. The treatments were consisted of two levels of pure nitrogen fertilizer (4.5 and 6% from urea) applied as solution on foliage, and two levels (60 and 90 kg/ha) applied through the soil and the control (applied in three stages at the end of vegetation growth and prior to reproduction stage.The experiment was carried out under Randomized Complete Block Design with 4 replications. Some characteristics such as plant height, tiller number, leaf length and width, stem diameter, canopy number or lateral stems, internodes length, root length and weight, shoot/root ratio and dry matter were measured. The results showed significant effect of fertilizer treatment on plant height, tiller number, stem diameter, canopy, root length, root weigh, shoot/root ratio and dry matter yield at 1% and leaf width at 5% levels. The highest plant height, tiller number, canopy, root length and weight was absorbed in the 90 kg/ha treatment (solid nitrogen application in the soil). Whereas, the highest biological yield observed in the 60 kg/ha treatment (solid nitrogen in the soil). Spraying 6% of pure nitrogen on foliage had the highest effect on shoot/root ratio.