Abstract:The purpose of this study was to investigate the response mechanism of carbonnitrogen metabolism on different drought and shading conditions for A. indica seedling, and enrich the theoretical basis for exploring the matter conversion and metabolic pattern of A. indica. In this work, twelve potted plants with four drought stress levels and three light levels were set up to determine the activities of major carbonnitrogen metabolism enzymes, the contents of some metabolites, and index of growth. The results showed that: (1) under the condition of drought stress, A. indica can maintain a smaller variation in height and diameter by regulating the activities of carbonnitrogen metabolism enzymes such as Sucro synthase (SS), Sucrose phosphate synthase (SPS), Nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase (GOGAT), as well as accumulate of more soluble sugar, soluble proteins and free prolines. (2) Under the condition of shading, slight shading can lead to a sharp decline in the activities of the carbonnitrogen metabolites and the contents of metabolites in A. indica leaves, which severely inhibits the growth of seeding. (3) Under the conditions of drought stress and shading, shading (drought stress) can alleviate the adverse effects of drought (shading) on the primary metabolism and growth of A. indica to some extent. Our research found that A. indica has a strong drought resistance, appropriate drought stress (SRWC>35%) can promote cell carbonnitrogen metabolism, but not conducive to the accumulation of organic matter. Meanwhile, seedling has a high demand for light, and slight shading will affect its carbonnitrogen metabolism and growth seriously. In the process of seedling cultivation in the future, we suggested that should provide as much water and light as possible. The negative effects of drought on seedling growth can be mitigated by shading, while insufficient light needs to properly control the water.