Trichirus spp. was caught 13,189 metric tons in 2020 with an production value of 1.3 billion NT, it became one of the important economic species around the coastal and offshore of Taiwan. In order to understand the temporal and spatial distribution and species composition of cutlassfish fishing hotspots, this study focuses on the acoustic survey, environmental data, and biological sampling in the northern waters off Taiwan. In addition, we sample cutlassfishes for species composition analysis and reproductive biology research. This study uses histological methods to identify the developmental status of cutlassfishes, and analyzes its gonadosomatic index (GSI), fecundity, size at maturity and spawning period to explore the reproductive biological characteristics of the cutlassfishes in waters off Taiwan, as a reference for future resource analysis, assessment and management.