Two field experiments carried out at Sakha Agricultural Research Station during the two seasons of 2008/2009 and 2009/2010 to study the effect of planting and harvesting dates on the growth ,yield and oil component of Melissa officinalis ,L .Two planting date , spring cultivation   (11^th March ) and autumn cultivation (24^th October) in the two seasons and two harvesting date 1- spring cultivation, the first harvest was done in the middle of  July and the second in the third week of October 2-autumn cultivation, the first harvest was done in the middle of June and the second in the first week of  October in the two seasons .The obtained results showed that the favorable planting date in kafr El-sheikh Governorate is spring planting which produced significantly the highest plants, more branches ,increased leaf area , the heaviest weights of fresh and dry /plant and dry yield /fed, maximum chlorophyll a, b and total chlorophyll , increasing N,P and K% , oil % and oil yield/plant and /fed. Concerning essential oil constituents geranial (citral A) were the major component of spring oil followed by camphene .Meanwhile, neral (citral B) was the major component of autumn oil , followed by geranial (citral A).The second harvesting time gave better results in most parameters than the first harvesting time .From the obvious results we can conclusion to cultivate Melissa officinalis,Lin the spring and harvesting it after 219 day (Time of flowering).