This study was carried out at the farm of Rice Research and Training Center (RRTC), Sakha, Kafr El-Sheikh, Egypt. Three CMS lines as female parents and three restorer lines as male parents were used to produce nine F₁ hybrids by lines x testers mating design to determine the heterosis, as well as gene action of yield and its components.  Both general and specific combining ability variances were found to be significant for most of traits. IR69025A/G181R hybrid yielded the highest number of grains/panicle, filled grains panicle^-1 and panicle weight. On the other hand, the number of days to heading, all hybrids exhibited significant negative heterobeltiosis expect the hybrid IR69025A/G181R. These hybrids appeared to be desirable for earliness.     The results also showed that most traits were controlled by the effects of both general combining ability (GCA) and specific combining ability (SCA) for the CMS and restorer lines.  The GCA was found to be more effective. In addition, the study revealed the heterosis presence over better parent (BP%), for yield and its components.