Two field experiments were conducted at the Rice Research and Training Center (RRTC), Sakha, Kafr El-Sheikh, Egypt in 2004 and 2005 growing seasons. The present attempt aimed to study the effect of three different spacings (20 x 15, 20 x 20 and 20 x 30 cm) and three number of seedlings/hill (2, 4 and 6 seedling/hill) on growth, grain yield and its components of two rice cultivars (hybrid rice SK2047H and Giza 178, inbred rice). The most important findings of this research could be summarized as follows: Significant differences were detected between the two rice cultivars in growth, grain yield and its components in the two seasons. The hybrid rice cultivar, SK2047H significantly exceeded the inbred rice cultivar, Giza 178 in growth characters, grain yield and most of its components. Hybrid SK2047H recorded the highest plant height, dry matter production, crop growth rate, leaf area index, chlorophyll content, biomass production, number of panicles/hill, panicles weight, 1000-grain weight, number of filled grains/panicle, grain yield as well as harvest index.                 Seedling planted at a sparse spacing (20 x 20 and 20 x 30 cm) produced higher leaf area index (LAI), highest value of light penetration, panicle weight, number of filled grains/panicle, grain filling period than seedling planted at a dense spacing (20 x 15 cm). Closer spacing (20 x 15 cm) gave higher dry weight, crop growth rate (CGR), plant height, sterility percentage than wider spacing. In the same time seedlings plant at 20 x 20 cm was benefit for rice growth and grain yield where, produced the highest number of panicles/hill, biomass, yield, grain yield (t/ha) and harvest index.                 Crops planted at two seedlings per hill gave significantly higher panicle weight, 1000-grain weight, grains filling period and harvest index (HI). While, six seedlings/hill resulted in lower in panicle weight, 1000-grain weight, number of filled grains/panicle, number of panicle/hill, biomass yield, harvest index and grain yield. In the same time, gave higher dry weight, leaf area index and sterility % compared with two seedlings/hill. Two or four seedlings/hill recorded the highest value of light penetration, number of filled grains/panicle, number of panicles/hill, 1000-grain weight, biomass and grain yield but, crop growth rate (CGR) and chlorophyll content were not affected.                 The interaction between rice cultivars and plant spacings was significant for DM, CGR and light penetration. Also, statistical analysis revealed significant interaction effect between cultivars and no. of seedlings per hill for 1000-grain weight, sterility %, number of panicles/hill and grain yield. In addition, this effect between spacing and number of seedlings/hill was significant for light penetration.                 For getting high yield, the hybrid rice (SK2047H) should be transplanted as two seedlings per hill in a 20 x 20 cm spacing. As for the inbred rice (Giz 178), it should be transplanted as four seedlings per hill at the same aforementioned spacing.