Osmoconditioning and hardening effects for the seed germination of normal and naturally aged rice seeds were studied through analyzing the total sugars and α -amylase activity. The normal seeds which used to have high germination rate accelerated germination with the osmoconditioning at the suboptimal temperature of 17~circC . On the other hand, the aged seeds did not affect germination rate at 25~circC , while increased germination rate and accelerated germination a little at 17~circC , Hardening of aged seeds increased germination rate by 10-15% compared with control seeds at both 17 and 25~circC and accelerated germination. Total sugar content and α -amylase activity of normal seeds were higher than did aged seeds. The aged seeds with treatment of osmoconditioning and hardening increased total sugar content and α --amylase activity, but hardening was more effective than osmoconditioning. The α --amylase activity was positively correlated with the total sugar content and germination rate.