The effect of seaweed extracts as a liquid fertilizer on growth, yield and biochemical constituents of faba bean was studied. The seaweed extracts were prepared from Sargassum latifolium, Halimeda opuntia collected from the Red Sea coast and Ulva rigida collected from Mediterranean Sea coast. The algal extracts used as foliar spray in a field experiment enhanced the faba bean growth criteria. Root parameters (root fresh and dry weights, root length number of root nodules, nitrogenase enzyme activity of root) and shoot parameters (shoot fresh and dry weights, shoot length), also the pigment content, number of tillers,  number of pods/ plant, grain yield, straw yield and seed index were increased. Some biochemical metablites (total carbohydrates, total protein and also the percentage of N, P and K) of seeds increased by seaweed extract application.