Abstract: Carboxymethylcysteine (CMC) is a common drug for the clinical treatment of chronic obstructive pulmonary disease, yet its long-term use can cause severe irritation to the gastrointestinal tract.As the substrate of nitric oxide (NO) synthase (NOS), L-arginine can be converted in the body into NO beneficial to the cardiovascular system, the gastrointestinal tract and so on.As a basic amino acid, L-arginine can be salified with some compounds containing acidic groups to improve the water solubility of the parent drug and may enhance the activity and alleviate side effects due to NO release.In this study, we designed and synthesized carboxymethylcysteine L-arginate (CMCA), and tested its physico-chemical properties, and the abilities to scavenge reactive oxygen species (ROS), inhibit apoptosis and release NO in cigarette smoke-induced injury model of human bronchial epithelial cells.The results revealed that CMCA is superior to CMC or L-arginine in that it could capture ROS, release NO and suppress apoptosis, suggesting that CMCA is worthy of further research and development.