Abstract The species composition, abundance, body lengths and stages of chaetognaths in relation to environmental factors at nine stations in Kaoping coastal waters were investigated during June 2001 to March 2002. In the surface tows, 20 species of chaetognaths, belonging to 10 families and 4 orders, were found, with the mean abundance of 17753 ¡Ó14593 ind./ 100m3. The 4 most dominant species, Flaccisagitta enflata, Aidanosagitta crassa, Sagitta bipuncata and Ferosagitta ferox, comprised > 80% of total chaetognaths. Flaccisagitta enflata was the most common and abundant species and occupied 53% of total chaetognaths. In 100m oblique tows, 21 species of chaetognaths, belonging to 11 families and 4 orders were found, with the mean abundance of 23535 ¡Ó 18696 ind./ 100m3. The 4 most dominant species were Flaccisagitta enflata, Aidanosagitta regularis, Serratosagitta pacifica and Aidanosagitta crassa, and comprised 77% of total chaetognths. Pseudosagitta lyra was the species found only in the 100m oblique tows. The abundance of chaetognaths changed with seasons and had the highest abundance in summer and the lowest in late autumn. The relation between abundance of chaetognaths showed significantly negative relationship with salinity but not for temperature, and had larger variation when salinity > 32 o/oo. Multi-Dimensional Scaling (MDS) method was used to elucidate the variation of chaetognaths community among seasons and stations. The community structure of chaetognaths had somewhat difference among seasons, with higher similarity between August and November, but these two months showed apparently different from June and March. The variation of chaetognaths community among stations was different seasonally, with higher in August and lower in March and June. Furthermore, three species groups were distinguished and their distribution patterns were herein disscussed. The Stage¢¹of chaetognaths dominated in this study area and occupied > 70 % of total count, and the number decreased rapidly following the developmental stages. The most dominant species, Flaccisagitta enflata, was also dominated by stage¢¹throughout the year, implied it might breed in the whole year. The body length of chaetognaths increased apparently with increasing of developmental stages, but overlapped among stages due to the wider variation in each stage.