Abstract: Two field experiments were carried out in Tag AL-Ezz, Agricultural Research Station Farm, ARC, Dakahlia Governorate during 2003 and 2004 seasons. The main objectives of this investigation were to study the genetic purity for four rice varieties through their seed classes and study the morphological characters of the studied cultivars at different growth stages. The main results could be summarized as follows: Giza 177 cultivar was identified by low flag leaf area, narrow angle of the flag leaf, pale straw grain colour and partly awned. Giza 178 cultivar was characterized with thin seed width, high flag leaf area narrow angle of the flag leaf, high number of tillers/hill and gold grain colour. Sakha 101 cultivar was identified by short plant height, late time of heading, large angle of the flag leaf, straw grain colour, absent awing and strong lemma and palea pubescence. Sakha 102 cultivar was identified by tall plant height, thin culm diameter, straw grain colour and partly awned. The analysis of SDS-PAGE had significant effect of studied cultivars at different classes. Planting with basic seed produced highest number of secondary branches/panicle, number of grains/panicle, panicle density, panicle weight, 1000 grain weight and grain yield (ton/fed). Planting using basic seed of Sakha 102 and Giza 178 cultivars produced tallest plants, harvest 1000 grain weight and grain yield/fed, respectively. It could be recommended that seed has been produced under a seed certification program are the best for high grain yield due their high vigor, viability and genetic purity.