Abstract: The water stress was simulated to study the effect of the endophytic fungi Botrytis sp.（C1）or Chaetomium globosum（C4）on Chrysanthemum morifolium in the adverse circumstance. C. morifolium plantlets which were inoculated with C1，C4 and cultured 60 days in the pots were stressed by 30% PEG6000 solution. SOD activity，POD activity，PAL activity，root activity，MDA content and soluble protein content were determined at 0，3，6，9，12，15 days after treatments，and the biomass of C. morifolium were also determined at 15 days after treatment. The results showed that the biomass of C1，C4 group and the control reached 4.1，4.4 and 3.3 g respectively，and all treatments got significant deviation（P < 0.05）. With PEG treatment，the root activity and PAL activity of the control were more sensitive at the first period of PEG stress，while fungi treatment groups were stabled，and stress reactions were delayed by fungi treatment. MDA content of the two fungi treatments reached the peak values with PEG stress for 3 days，while the control continues increased and got the peak at 6 days with PEG treatment. When at the later period of the stress，root activity，PAL activity，and MDA content of all treatments had no significant deviation. POD activity and soluble protein content of all treatments were increased firstly and decreased then，but all treatments had no siginificant deviation. Endophytic fungi can increase the drought resistance of C. morifolium in a short period of water stress.

Key words: Chrysanthemum morifolium, PEG6000, Botrytis sp., Chaetomium globosum, drought resistance, antioxidation