【Objective】The effect of drought stress on some physiological indices in cucumber seedlings was studied in order to elucidate mechanism of drought tolerance and help in breeding drought resistant varieties of cucumber.【Method】Hoagland solution culture method was used to investigate the dynamic of several physiological indices， such as superoxide dismutase （SOD） activity， proline， malondialdehyde （MDA） and soluble protein contents in the leaves of cucumber seedlings under different levels of drought stress simulated by PEG-6000. 【Result】With increasing PEG-6000 concentration， the proline and MDA contents increased gradually， while the SOD activity and soluble protein content increased initially and then decreased. 【Conclusion】The physiological indices， viz.， proline， MDA and soluble protein content， and SOD activity may be used to evaluate drought tolerance in cucumber.