To study the effect of five levels (150, 190, 230, 270 and 310 kg N/ ha) of nitrogen and four potassium levels (50, 100, 150 and 200 kg K₂O/ ha) on productivity and quality of sugar beet variety Nina, a field experiment was conducted at Experimental Research Station, Al Kufra Production Project (latitude of 4-12°N and longitude 17-23° S), Libya in 2014/ 2015 winter season. A split plot design in three replication was done. Obtained results revealed that fertilized plants with 310 kg N/ ha produced the highest root diameter (12.17 cm), foliage weight/ plant and hectare (346.93 gm and 30.804 ton), respectively, highest sucrose, purity and extractable sugar percentages (17.44, 79.15 and 15.43), respectively. The highest potassium fertilizer level (200 kg K₂O/ ha) produced the largest root diameter and weight (10.78 cm amd 989.52 gm), highest root and sugar yields (85.473 and 12.432 ton/ ha), highest purity and extractable sugar (73.59 % and 14.51%). However, 310 kg N/ ha combined with 200 kg K₂O/ ha produced the heaviest roots (1140.60 gm) and maximum root and sugar yields (89.225 and 14.088 ton/ ha). Also, 310 kg N/ ha combined with any of the studied potassium levels produced the highest root diameter, sucrose and extractable sugar percentage and root potassium content.