Two field experiments was established at Sakha Agricultural Research Station during the two seasons of 2008/2009 and 2009/2010 to evaluate the effect of planting spaces and active dry yeast on the growth ,yield and oil components of Melissa officinalis ,L .Three planting spaces (30, 40 and 50 cm) and four applications of active dry yeast (control, 5, 10 and 15gm / l) were used in the two seasons. The obtained results showed that wider plant spacing showed the greatest effect on growth parameters and chemical constituents. Similarly, active dry yeast levels had a promoting influence on most of the vegetative growth parameters and accelerated essential oil accumulation and chemical constituents including chlorophyll a ,b and total content and N,P and K%. The wider space between plants (40 or 50 cm) combined with maximum rate of dry yeast (10 or 15g/ l) had a favorable effect on the most growth characters and chemical constituents. The main constituent of the essential oil was, geranial (citral A) followed by camphene. Generally, it can be concluded that there is no significant difference between wider distance (50 cm) and medium one (40 cm) and rate of dry yeast (10 and15g/ l).So, it can be recommended to cultivate at distance of (40 cm) combined with applying (10 g/ l) of active dry yeast.