Our investigation of the seaweed extracts, Ulva lactuca. The biological activities antioxidant, antimicrobial activity, antifungal and haemolytic activity of ethy-ether and ethyl-acetate extracts from the seaweed, Ulva lactuca were investigated. They were separately extracted using ethyl-ether and ethyl-acetate from dried samples at room temperature and freeze dried. Seaweed extracts were found to cause significant free radical scavenging effects on DPPH (1,1-diphenyl-2-picrylhydrazyl). Seaweed extracts had not significant haemolytic activity against human erythrocyte. This extracts exhibited in vitro broad-spectrum antimicrobial activity of gram-negative, gram-positive bacteria and without antifungal activity.