Abstract: Active oxygen metabolism and accommodation of Chamaecrista spp. CPI86134 under chilling stress in seedling period were studied. The results show that net rate of O₂ generation, H₂O₂ and malondialdehyde (MDA) contents, and rate of leakage of electrolyte significantly increase with enhanced and longer chilling stress; the contents of scavenging enzymes (SOD, POD, AsA-POD) also fast increase in 48 hours under chilling stress, then slowly drop. So we can conclude that the enhancements of scavenging enzymes activity are the adaptive response to chilling stress, and the severe accumulations of O₂ and H₂O₂ result in the lipid peroxidation and the damage of lipid system.