The present study was aimed to evaluate different parts of Melissa officinalis plant from biochemical composition and thrombolytic activity. Methods: Leaf and stem part of Melissa officinalis growing naturally were assessed for total phenolic, total flavonoid and total tannin contents. Both parts were examined for the invitro thrombolytic activity. Results: Significant greater amount of total phenolic (27.882 __ampersandsignplusmn; 0.544 mcg GAE\g DW) , total flavonoid (256.708 __ampersandsignplusmn; 1.447 mcg QE\g DW) and total tannin contents (424.266 __ampersandsignplusmn; 1.026 mcg GAE\g DW) were expressed by the leaf part (p __ampersandsignlt; 0.01) in comparison to the stem part. A significant thrombolytic activity were expressed by both parts in comparison to the control negative (distilled water) (p value __ampersandsignlt; 0.0001) at all tested concentration rage. Greatest thrombolytic activity were detected at high concentration (1000 mcg\ml) for both parts. Generally the thrombolytic activity exhibited by the leaf part was higher than that of stem part. Conclusion: From the results of study we concluded that leaf part of Melissa officinalis was richest in phytochemical constituents with moderate thrombolytic activity.