The shrub Caraganas stenophylla is widely distributed and used as a sand binding plant on moving sand dunes in China. The physiological mechanisms involved in C. stenophylla responds to coverage with sand are unknown. Therefore we investigated responses to three levels of sand burial based on plant height: light (1/4 plant height), modest (2/4 plant height), and severe (3/4 plant height) as compared with controls (no sand burial). To understand the physiological and molecular regulatory mechanisms for C. stenophylla in adaption to sand burial, changes in length of different parts of plant stems were observed 3 days (d), 6d, 9d, and 12d after sand burial treatment and contents of malondialdehyde (MDA) and activities of antioxidant enzymes peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) were measured 6d and 12d after treatment. CAT and POD isozymes were also analyzed in leaves 6d after sand burial treatment. Results showed that 6d after sand burial treatment, growth rates of different parts of the stem increased as burial deepened. At the same time, MDA content in the leaves decreased and activities of CAT, POD and SOD in different plant parts increased under light and modest sand burial treatments. Growth rate was higher 12d after treatment than at 6d after treatment but the leaves under sand died. Meanwhile, MDA content and SOD activity were markedly increased by 64% and 121% in leaves above sand under modest and severe sand burial. CAT activity in leaves above sand was also higher under light and modest sand burial. POD activity in the leaves under different depths of sand burial was higher by 308%-104%. SOD activity was higher by 32% and 233% in the leaves with modest and severe sand burial compared with controls. This suggests that the higher growth rate during 7-12d was positively correlated with higher activities in protective enzymes, and increases in antioxidant capacity after sand burial, which might have played an important role in the stem growth and the balance of oxygen free radical metabolism. Analysis of isomers of antioxidant enzymes by native-PAGE and activity staining revealed new isoforms, CAT III and CATII, in the leaves with modest and severe sand burial, and their concentrations were enhanced by sand burial. There are six isoforms of POD; POD II intensity increased with increasing depth of sand burial; a new band, POD IV, was observed while POD I and POD III disappeared. This suggests that during acclimation to sand burial, the activity of protective enzymes is highly related to differential gene expression. Isofo rms of CAT, POD and SOD in the leaves over sand were similar to those under sand 6d after sand burial, which indicates that the signal of sand burial was transduced from leaves under sand to leaves over sand, resulting in the whole plant receiving the signal of sand stress to adapt to sand burial. Therefore, differential gene expression plays an important role in increasing protective enzyme activity to maintain the balance of oxygen free radical metabolism in C. stenophylla.