Abstract: The plants of Acacia mangium QLD19835 clone were studied under the chilling stress in the phytotrons. The plants suffered from temperature changes from30 ℃ to 6 ℃. The results showed that the electrical conductivity, the contents of soluble sugar, proline, soluble protein in the phyllodia (petioles) increased in the low temperature stress. The activities of ATPase, catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) changed with chilling treatment. Under the stress of low temperature, cell membrane system was damaged and the electrical conductivity increased. The activity of ATPase decreased. These physiological changes might play an important role in protecting cell stability and promoting the enduring ability of plants to the low temperature. The results indicated that Acacia mangium QLD19835 clone had enduring ability to the stress of low temperature.