Abstract: Antimicrobial peptides are a group of small peptides with broad-spectrum antimicrobial activities, which have been studied for several decades.Antimicrobial peptides are thought to be "natural antibiotics".Marine antimicrobial peptides are considered to be one of the important components of innate immune defense system in fish, shrimp, crab, shellfish and other marine animals.Marine antimicrobial peptides play an important role in the defense of exogenous pathogens in the marine environment.The development and application of marine antimicrobial peptides not only has an important prospect of medical development, but also is an important safeguard to reduce antibiotic contamination and achieve the healthy breeding of marine animals.Here we make a brief introduction of the research and application prospects of antimicrobial peptides from marine fish and crustacean, and the source and classification of antimicrobial peptides, structural characteristics and biological activity will be clarified.