Field experiments were carried out in El-Mattana Ag­ricultural Research Station at Oena Governorate during two harvest seasons 1998/2000 and 2000/2001, including plant crop and its first ratoon crop to study the response of some sugar cane va­rieties (G.T.54.9,G.87-37, G.87-55 and F.160) to different levels of K fertilizer (0.24,48 and 72 kg K₂0 /fed.). Results obtained show that G.T. 54-9 variety surpassed the other three varieties in number of millable cane /m², length, diameter and yield of millable cane and sugar, while G.87-37 variety gave the highest values of T.S.S.% and sucrose % in both crops. Concerning the K fertilizer, number of millable cane / m'. millable cane diameter, cane yield, T.S.S.% sucrose % and sugar yield were significantly increased by K levels in plant crop and it first ratoon crop. In general all traits increased by increasing K fertilizer compared to control treatment. The highest theoretical sugar yield was obtained from G.T.54-9 with 72kg K₂0 /fed in plant and its ratoon crop.