The objective of this study was to evaluate the effect of row spacing (25, 50, and 75 cm) and plant density variation (20 and 30 plant / m²) in grain yield and yield components of soybean . The experiment was carried out from November /2008 to May /2009, with four transgenic soybean genotypes from Embrapa ( BRS 255 RR , BRS Pampa RR , BRS Taura RR e BRS Tertúlia RR ). The experimental design was a complete split block with three replications . For all genotypes the plant density of 20 pl / m² had no difference in grain yield as 30 plant / m², which is the recommended plant density for the November sowing . Furthermore , the row spacing of 75 cm had the smallest grain yield when compared to 25 and 50 cm , and this was mainly due to a reduction of the number of pods / m² .

Key words: Glycine max (L) Merril, row spacing, plant population.