Two field experiments were carried out at the experimental farm of El-Minia University during 2003/2004 and 2004/2005 seasons to study the effect of sowing dates (20^th Sep., 10^th Oct. and 1^st Nov.), hill spacing (15,20 and 25 cm.) and Potassium-rates (0,24 and 48kg K2O/fad.) as well as their interactions on yield, yield components and quality of sugar beet, c.v. Raspoly. The experimental design was split-split plot with three replications The main results could be summarized as follows. All characters for yield and its components and quality were significantly affected by sowing dates. Sowing beet plants on 10^th Oct. gave the greatest values of root length, root diameter, root fresh weight, foliage fresh weight/plant, yields of root, top and sugar. as well as TSS% and sucrose% in both seasons, while purity % recorded adversely trend in both seasons. Sowing beet plants on 1^st Nov. Produced the lowest averages from all traits, except purity % in the second season, while sowing beet plants on 20^th Sept. gave the highest average of purity % in the first season and vice-versa in the second one. Hill spacing of 20 cm. gave the highest value of root length and diameter, foliage fresh weight, yields f top, root and sugar as well as TSS % and sucrose % in both seasons, while purity % resulted the lowest one in both seasons. On the other hand hill spacing of 15cm. between beet plants produced the lowest averages from this traits in both seasons, except root yield/ fad and TSS % where the lowest values from this traits resulted from hill spacing of 25 cm. between plants the greatest values of root fresh weight as well as juice purity % obtained from 25cm. between hills in both seasons. All characters significantly increased with increasing Potassium rate up to 48 kg K₂O /fad except purity % in the two seasons. The interactions indicated that the highest yield from root and sugar /fad was obtained by sowing beet on 10^th Oct. at 20^th cm between hills with 48kg k₂o/fad.