| Summary: | <i>Cunninghamia</i> plays an important role in China’s southern forest industry in the face of increasingly arid climate; thus it is urgent to identify and screen drought-tolerant varieties. In this study, 2-year-old seedlings of <i>C. unica</i> and <i>C. lanceolata</i> from four provenances were subjected to water-break tests, and their physiological responses to different drought conditions were observed. The results showed that with the aggravation of drought stress, <i>C. unica</i> had more stable changes in relative water content (<i>RWC</i>), water potential (<i>Ψw</i>) and intercellular CO<sub>2</sub> concentration (<i>Ci</i>) with more cumulative amounts of proline (<i>PRO</i>) than <i>C. lanceolata</i>, and its H<sub>2</sub>O<sub>2</sub> maintained at a lower level, along with antioxidant enzyme activities decreasing later as compared with <i>C. lanceolata</i>. Moreover, comprehensive evaluation showed that <i>C. unica</i> had a higher drought tolerance than <i>C. lanceolata</i> as a whole, which could have been shaped by maintaining <i>Ψw</i> and opening stomata in its relative drought conditions. This work provides a theoretical basis for understanding the drought tolerance of <i>C. unica</i> and <i>C. lanceolate</i> individuals, so as to accelerate selective breeding in Chinese fir.
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