Abstract:To examine the physiological responses of Z. schneideriana seedlings to drought stress and to screen out the physiological indexes of drought resistance, a pot water control test was conducted. The drought resistance was also evaluated based on the membership function values. Two materials (Z.schneiderana ‘Hentiangao’and common Z.schneideriana grafted seedlings) were studied under three water conditions: light drought (LD), moderate drought (MD) and severe drought (SD). The results showed that with the increase of drought stress, the contents of the relative electric conductivity (Rec), malondialdehyde (MDA), water saturation deficit (WSD) and free proline (Pro) of the two testing materials were increased. And their peroxidase (POD) activity, superoxide dismutase (SOD) activity and chlorophyll (Chl) contents also increased with the changed drought stress, as a 'parabola' trend. The SS contents increased with the increase of drought stress for Z. schneideriana ‘Hentiangao’, but increased first and then decreased for Z. schneiderian. Principal component analysis based on 8 drought stress indexes hinted that Rec, MDA, WSD, Pro and POD had the close relationships with the drought resistance of Z.schneideriana, and could be used to evaluate its drought resistance. The calculated membership function values of the 8 physiological indexes and the comprehensive index from the principal component analysis indicted that the drought resistance of ‘Hentiangao’ (0.58) is stronger than the common Z. schneideriana’s (0.56). Considering the drought resistance of ‘Hentiangao’ is match with oriental arborvitae, it can meet the application requirements of urban landscape and highway greening from the point of drought resistance.