Abstract: Nitric oxide(NO)is a vital signal messenger in human and generated by nitric oxide synthase including endothelial nitric oxide synthase(eNOS), inducible nitric oxide synthase(iNOS)and neuropathic nitric oxide synthase(nNOS). NO has important regulatory function on the immune system, nervous system and many other physiological systems. Endogenous NO can enhance the function of the vascular system and endothelial cell survival, and inhibit platelet accumulation and leukocyte infiltration. Excessive production of NO may damage tissues by cytotoxic and cytostatic effects. Thus, NO plays a dual role in physiology and pathology. This paper gives a brief review on regulatory effects of NOS-NO system by traditional Chinese medicine during the recent five years, so as to provide some clues or references for the treatment of related diseases and scientific evidene for reasonable and effective clinical application.