Abstract: To evaluate the physiological response of Arenga pinnata to drought stress and re\|watering process， activity of superoxide dismutase （SOD）， the contents of proline， soluble protein and malondialdehyde （MDA）， relative electrical conductivity and chlorophyll contents in the leaves and roots of A.pinnata were determined when the two-year seedlings were subjected to 0 （control）， 7， 14， 21 d drought stress， and 3， 6 d re-watering. The results showed as follows: The SOD activities in leaves varied significantly under different treatments， and SOD activities in roots under drought stresses and re\|watering were significantly higher than those of the control. The contents of proline increased significantly under 21 d drought stress, and decreased drastically then. However， the contents of soluble protein in leaves and roots decreased significantly under 14 and 21 d drought stress， and increased drastically during re-watering process. MDA contents in leaves and roots showed the contrary change trends. The relative electrical conductivity in leaves and roots increased drastically under 14 and 21 d drought stresses, then decreased during re-watering process. The contents of chlorophyll increased and reached to the maximum under 21 d drought stress. The dynamic tendencies of proline content， soluable protein content and relative electrical conductivity in leaves were similar to those in roots. However， different change trends of SOD activities were observed in leaves and roots， which also for MDA contents. The physiological change trends indicated the synergistic effects in leaves and roots of A.pinnata to drought stress and re-watering process.

Key words: Arenga pinata, drought stress, re-watering, leaves, roots