The present study was aimed to investigate the planting dates effects on yield associated traits and also determining stability of the result of factor analysis and stepwise regression analysis in different planting dates of rapeseed genotypes at Biekol Agriculture Research Station during 2011-12 cropping season. Result of split plot analysis exhibited significant genotypes effects for phenological traits, yield components and seed yield indicated significant differences of the genotypes for these traits. All the traits except 1000-seed weight were significant affected by planting dates. Significant positive correlation was detected between days to flowering and days to maturity in four planting dates. The correlation between seeds per pod with 1000-seed weight and seed yield were significant in all planting dates. Seed yield and biological yield had also significant and stable correlation. Based on stepwise regression analysis seeds per pod had important role in first and second planting dates, but in third and fourth planting dates, pods per plant was more important than other yield components for seed yield prediction model.