Abstract: In order to evaluate the influence of plant densities on LAI, solar radiation absorption, light transmission and yield components of three spring rape seed cultivars, this research was conducted on the basis of split plot layout with completely randomized block design with 3 replications. Plant densities in main plots were 40, 80 and 120 plants per m², and rapeseed cultivars in secondary plots were Sarigol, RGS003 and Hyola401. This research was conducted at research farm, experimental research station, Shahrekord city, Shahrekord province, Iran. Plant density had significant influence on LAI, solar radiation absorption, light transmission, the number of pods per plant and seed yield. LAI, the number of pods per plant and the number of seed per pod was significantly influenced by cultivar. Plant density and cultivar interaction had significant effect on LAI. The highest LAI, solar radiation absorption, plant height was obtained in 120 plants per m²; however, 40 plants per m² had obtained the maximum number of pods per plant and the number of seed per pod. 80 plants per m² had obtained the maximum seed yield. The maximum light interception also obtained by this treatment. RGS 003 had obtained the highest LAI and solar radiation absorption. Although, the maximum number of pods per plant and number of seed per pod was related to Sarigol and Hyola 401, the maximum seed yield was obtained in RGS003. So, it seems that plantation of RGS003 and 80 plants per m² was suitable to producing high seed yield.