This study aims to describe the spatial and temporal distribution of Platycephalids and the biology of the dominant species Suggrundus macracanthus, in the coastal waters off southwestern Taiwan. A beam trawl was adopted to collect fish samples from 7 stations, including Jiading, Zouying, Jhongjhou, Linyuan, Dapeng Bay, Linbian and Fangliao. Samplings were carried out on a 1-2 month interval, started from June 2000 and ended in August 2005. In total, 3,780 specimens were collected, including 9 genus 11 species. The distribution of Platycephalids varied in station, water depth and season. The lowest abundance were recorded at Jiading, then decreased from Zouying to Linyuan, and then increased southwards. Platycephalids eived more abundant in depth 25-55 m, and the number increased with depth 15-35 m. The highest abundance occurred from spring to summer. S. macracanthus (74%) were the top dominant species. S. macracanthus spawn once a year during February to April, with a peak in the frequency distribution of egg diameter. The recruitment of S. macracanthus occurred in the period from June to July, at near-shore waters of 15 m depth with mud and sand substrata. S. macracanthus take epibenthic shrimp as the major diet accounts for above 68%, including 59% of Metapenaeopsis palmensis. Other food items still had the fish, crab, Mollusca and Amphipoda. S. macracanthus juveniles nearly didn¡¦t ate crab, but the adult ate crab up to 12%.