This book provides a detailed description on ecology and phytosociology of weeds of the main habitat types in El-Behira Governorate,Egypt.Also shed light on the economic importance of some selected plants by examining the nutritional composition of them as well as examine antimicrobial and antioxidant activities.The selected plant species may be added to the non conventional forage to be used as a rich green fodder for livestock in both summer and winter seasons due to high nutritive value and used as a raw material for various uses in industrial and pharmaceutical purposes due to relative high content of phenolics, tannins, saponins, alkaloids, flavonoids and high antioxidant capacity.