The present study was carried out at El-Mattana Agricultural Research Station Farm at Qena Governorate, Upper Egypt during the two seasons of   2003 / 2004 and 2004 / 2005  as plant cane ( Virgin cane ) to study the effect of harvest dates ( 9,10,11,12,13 and 14 months after planting  ) on yield and juice quality of some promising sugar cane varieties ( G.84/47 , PH 8013 , G.95/21, G.95/19, G.98/28  and G.98/87) in addition to the commercial variety ( G.T.54/9 ). Under the environmental conditions of Qena Governorate , the promising varieties PH8013 and G.84/47 as well as the commercial variety G.T.54/9 gave the best cane yield, best juice quality and hence sugar yield per area unit. Maximization of sugar yield could be achieved after 13 months of age for sugar cane varieties PH.8013, G.95/21 and G.95/19 and these varieties were considered as intermediate maturing varieties,  while the varieties G.98/28, G.98/87 and G.T.54/9 gave maximum sugar yield after 14 months of age and these varieties were considered as late maturing varieties. On the other hand, G.84/47 variety could be harvested after 12 months of age and considered as early maturing one .