In order to supply quality seed for vegetation restoration in arid and semiarid areas of Northwest China, the effects of Platycladus orientalis seed storage under ultra-drying and accelerated aging were studied. The seeds were dried from 6.8% to 5.1%, 4.4%, 3.7% and 2.2% MC, respectively, in a desiccator with the silica gel. The germination energy, germination percentage, germination index and vigor index of the seed were investigated. After ultra-drying, groups of seeds were carried on the accelerated aging tests in an oven at 50 oC for 10, 20 and 30 d , respectively, and the physiological indexes, including relative conductivity, dehydrogenase activity and α-amylase activity were tested. The results show that the ultra-dried seeds with 3.7% MC have the highest germination energy, germination percentage, germination index and vigor index. After aging, the dehydrogenase activity and α-amylase activity of the group of seeds of 3.7% MC were higher than those of 6.8%, while the relative conductivity of the group of 3.7% is lower than that of 6.8%. It is feasible to ultra- dry the seeds with 3.7% MC.
