In order to study effect of different sowing dates on stigma yield and yield components in saffron. Field trials were arranged in split plot design was sowing dates (05-May, 05-Jun, 05-Jul, 05-Aug, 05-Sep and 05-Oct) as main plot and four ecotypes as sub plots (Mashhad, Torbat-jam, Gonabad, Birjand) in Mashhad at three distinct years (2009-11). The results from analysis of variance indicated significant differences between ecotypes and sowing dates in individual years, at last it is distincted that two Mashhad and Torbat-jam ecotypes had the highest stigma yield (98.6 and 92.5 mg/m2) in Mashhad climate. Also, the best sowing dates were 05-Jun to 05-July in Mashhad. It revealed that climate had significant effects on stigma yield and yield components, so that delaying in cultivation leads to decrease all agronomical traits of saffron. In other hand, results from metereological data indicated that average of temperature and average of sunny hours in comparison with average of percipitation and average of relative humidity, showed maximum effects on stigma yield and yield components, positively. Finally, results from phenotypic correlation indicated that stigma yield showed significant and positive correlation with all studied traits and results from step-by-step regression indicated that daughter corm number and corm fresh weight had positive and maximum direct effects to improve stigma yield. Therefore, it can be concluded that increasing cultivation density and selecting bigger corms are useful factor to increasing stigma yield.