To obtain some information on the change of antioxidant components of seeds during grain filling stage as affected by the sowing dates, lignan compounds were investigated according to days of flowering under different sowing dates. Sesamin and sesamolin contents showed significantly different by days of flowering and varieties. Both of sesamin and sesamolin content increased after flowering and reached highest at 40 days of flowering, but they started to decrease thereafter. Sesamin and sesamolin contents of sesame seeds changed with sowing dates. Generally, late sowing date of May 30 showed relatively higher accumulation rate of sesamin and sesamolin contents rather than other sowing dates, but overall patterns were a little different by varieties and lignan compounds. In case of variety Yangbaek, sesamin and sesamolin contents showed relatively higher at sowing date of May 30, but variety Yanghuck showed higher sesamin and sesamolin contents till 20 days of flowering when sowing date of May 30, but it showed to change that both lignan contents were relatively higher under sowing date of May 10.