This investigation was carried out during the seasons of 2003, 2004 and 2005 to study the effect of magnesium fertilization on vegetative growth, leaf mineral and chlorophyll contents, yield and fruit quality of "Costata" persimmon trees grown on calcareous soil at El-Beheira Governorate. Results were only taken in 2004 and 2005 seasons. In this respect, four rates (75, 100, 125 and 150 g/tree/year) of  both sulphate and chelated magnesium fertilizer forms were used in comparison with control. Each Mg fertilizer rate was applied in two equal doses at mid March and April, respectively. The data revealed that shoot length and diameter as well as area per leaf, were increased by raising Mg (sulphate or chelated) rate up to 125 or 150 g/tree/year. Also, N,P,K and Mg as well as total chlorophyll contents in leaves were significantly increased with increasing Mg fertilizer as compared to the control whereas, leaf Ca content was decreased. On the other hand, Fe, Mn and Zn were not affected in both seasons. Using 150 g/tree/year of Mg-sulphate and 125 or 150 g/tree/year of Mg-chelated significantly increased fruit set % and yield as number and weight of fruits per tree than the control. In addition, raising either Mg sulphate or chelated rate gradually increased average fruit weight, size, firmness and SSC value. However, acidity percentage and total tannin content in fruit juice were not significantly affected.                 Generally, adding 150 g/tree/year of Mg-sulphate or 125 g/tree/year Mg-chelated to the fertilization program of “Costata" persimmon trees. produced a higher yield with good fruit quality.