This Investigation was carried out at Nubaria Agricultural Research Station (30° 54´ N, 29° 57´ E, and 15m above sea level), Agricultural Research Centre (ARC), Ministry of Agriculture and Land Reclamation (MALR), El-Behiera Governorate, Egypt during 2016-2018 period to study the effects of application liquid humic acid on the soil of alfalfa forage yield and quality. Three irrigation water regime treatments (100%, 80% and 60%) of ETp and three humic acid rates (0 , 3 and 6 L/ha humic acid) were tested for their effects on alfalfa yield and quality in a split-plot design. As water requirements decreased forage yield significantly decreased in the 4 seasons for each year. No significant differences were found between the fresh or dry forage yields or leaf/stem ratio under 100% water requirement without humic acid and 80% water requirement with 6 L/ha humic acid. No significant differences were found between protein content under the interaction between irrigation water requirements and humic acid rate. Irrigation water use efficiency increased under water stress as an application of humic acid rate increased.