Striped marlin and blue marlin are largest apex predators distributed from tropical to temperate oceans. To investigate their movement patterns, pop-up satellite archival tags (PSATs) were deployed on striped marlin and black marlin using the traditional harpoon and longline fishery of southeastern Taiwan (Taitung). Depth, temperature and ambient light data were recorded by PSATs. In total, 4 striped marlin and 14 black blue marlin were tagged from Feb 2010 to June 2024 and PSATs remain affixed on the animals ranging from 10 to 360 days. Linear displacements ranged from 279 to 2,005 km from deployment to pop-up locations with average speeds of 3 to 30 km hour-1. Our horizontal movement tracks (Most Probable Tracks calculated by the Kalman filter) suggest that striped marlin and black marlin undergo distinct seasonal movement patterns. Striped marlin tagged winter and summer moved to South China Sea. Black marlin fishes tagged in spring and summer moved in a northerly direction to the East China Sea and those tagged in winter season moved in a southerly direction to the South China Sea. Diving depths ranged from the surface to ~258 m for marlin, and surface to ~258 m for black marlin. Ambient water temperatures ranges from 14.4°C to 34.4°C for black marlin, and 14.5°C to 30.0°C for black marlin. The distributions of time spent at depth have significantly different between daytime and nighttime diving activity. Tagged striped marlin and black marlin spent the majority of daytime in the surface mixed-layer to ~50 m and exhibited basking behaviour, and at nighttime they were confined exclusively to the surface. Depth distribution appeared to be limited by an 8°C change in water temperature relative to the warmest water (ΔSST analysis). Like many other istiophorid billfishes, striped marlin and black marlin diving behavior and preference for the surface water makes them particularly vulnerable to surface fishing gears. In the context of regional fisheries management and stock assessments, our study reports the first tagging data of wild striped marlin in northwestern Pacific Ocean.