This study was carried out at the experimental farm of Rice Researchand Training Center (RRTC), Sakha, Kafr El-Sheikh, Egypt, to studycombining ability and heterosis in a diallel mating design among six ricegenotypes (excluding reciprocals), using six varieties namely Sakha 101,Sakha 103,Giza177,Giza176 and Giza159 and BL1. An experiment was conducted during 2014, 2015 growing seasons and designed in a randomizecomplete block with three replications. Data were recorded on eleven traits;heading date, chlorophyll content, flag leaf area, plant height, number oftillers/plant, panicle length, panicle weight, panicle fertility (%),1000-grainweight and grain yield /plant. The results revealed that, the genotypes werehighly significant different in all studied characters. The crosses Sakha 103 ×BL1 and Giza177 x BL1 showed positive and significant heterosis for mid andbetter parents for most studied traits. The parent Giza176 was good generalcombiner for most studied traits. The cross Sakha 101 × BL1 showed positiveand highly significant of specific combining ability effects for grain yield and its components.