Abstract: To understand the comprehensive ability of ′Ziren′ walnut in response to drought stress, ′Ziren′ walnut from Ankang area was selected to analyze the physiological responses under drought stress. ′Ziren 1′ and ′Ziren 2′ were treated with PEG₆₀₀₀ for 3, 6, 9, 15 d, then the physiological index including the relative conductivity, malonaldehyde (MDA) content, autioxidant enzyme activities, and proline content were tested. The results showed that the physiological responses of ′Ziren 1′ and ′Ziren 2′ were similar under drought stress. In other words, the relative conductivity rate and MDA content were up-regulated, the SOD and POD activities were enhanced, and the proline content was increased. However, the relative conductivity rate and MDA content of ′Ziren 1′ were significantly higher than those of ′Ziren 2′, while the activities of SOD and POD enzymes were lower than those of ′Ziren 2′. These results indicated that the comprehensive drought resistance of ′Ziren1′ was weaker than that of ′Ziren 2′ exposed to the same treatment.