Abstract: Physiological characteristics of cutting seedlings of ten ancient tea plants from Karst region were investigated under water controlled conditions to unveil the possible mechanisms of cutting seedlings of ancient tea plants in response to drought stress and to screen out the drought resistant germplasms. The results showed that the relative water content，PSⅡ（F_v/F_m），stomatal opening rate，stomatal length and stomatal width were decreased. Meanwhile，the relative conductivity，content of the lipid peroxidation product（Malondialdehyde，MDA），contents of hydrogen peroxide（H₂O₂），superoxide radical（） producing rate and stomatal density were increased with the treatment intensity. One strong drought resistance material and five better drought resistance materials were selected from the ten ancient tea cuttings. The one-year field trial proved the subordinate function method based on physiological parameters could be used as a reliable method to screen out the drought-tolerant ancient tea germplasms.

Key words: tea plant, drought stress, physiological responds, drought resistance, evaluation