Two field experiments were carried out at the Experimental Farm of El-Serw St., Damietta Governorate during 2006/2007and 2007/2008 winter seasons on fodder beet (Beta vulgaris c.v. Vorochenger) to study the effect of gypsum and potassium fertilizer on yield and quality of fodder beet. The study included four gypsum levels i.e. zero (control), 5, 10 and 15 ton /fad. and four potassium fertilizer levels (zero (control), 36, 72 and 108 kg K2O/fad.). The experimental design was strip plot design with three replicates. Significant differences were recorded between different treatments and the treatment which received 15 tons gypsum/fad. and 108 kg K/fad. surpassed the other treatments in all the growth characters of fodder beet plants e.g. root length, root diameter, fresh and dry yield of roots and foliages. The same treatment was superior in quality characteristics, crude protein, ash and digestible crude protein but it gave the lowest value of crude fiber and total digestible nutrients. Meanwhile the same treatment was superior in nitrogen content but it gave the lowest values of phosphorus and potassium. It may be recommended that adding gypsum at a rate of 15 ton/fad and 108 kg K2O/fed improved fodder beet productivity under alkaline saline affected soils.