Litopenaeus vannamei is one of the important cultured species. However, due to the pathogen invasion and drastic climate change, the farming industry has been impacted and induced the stress response of L. vannamei leading to production reduced even death. The release of biogenic amines is considered as the primary response for regulating immunity and physiology of L. vannamei. Our previous study had been confirmed the effects of key enzyme and products in octopaminergic biosynthesis pathway of L. vannamei. The octopaminergic biosynthesis pathway is tyrosine→tyramine (TA)→octopamine (OA), which catalyzed by tyrosine decarboxylase (TDC) and tyramine beta-hydroxylase (TBH). Both OA and TA had been evaluated to enhance the immunity and pathogen resistance ability in L. vannamei. L. vannamei revived ≤1000?pmol shrimp−1 OA and TA showed significant increases in total haemocyte count, differential haemocyte count, phenoloxidase activity, respiratory bursts, phagocytic activity and clearance efficiency in response to the pathogen infection. The TDC and TBH had been cloned and characterized the functions and regulation in L. vannamei. LvTDC and LvTBH is confirmed to involve in the neuroendocrine regulatory network, and modulate physiological and immunological response, and LvTBH gene expression is alternated under hypothermal and pathogen-challenged stresses. All results indicate that key enzyme and products in octopaminergic biosynthesis pathway are participate in physiological and immune regulation of L. vannamei.