Abstract: The changes of the relative water content (RWC), soluble sugar (Ssug), soluble protein (Spro), malonaldehyde (MDA) and free proline (Fpro) of Juglans sigillata seedlings under different simulated water stress by means of treating with polyethyleneglycol 6000 (PEG-6000) solutions with different osmotic potentials. The results showed that the indexes of RWC, Ssug and Fpro could comprehensively reflect the drought resistance of J. sigillata seedlings. Along with the development of drought stress, the RWC decreased gradually, the Ssug content increased, the contents of Spro, MDA and Fpro first dropped slightly and then increased gradually.