Tingginya produktivitas mangrove menjadikan hutan mangrove memiliki fungsi ekologis yang pentingbagi makhluk hidup, yaitu sebagai tempat memijah, pembesaran dan mencari makan. Biota yang hiduppada ekosistem mangrove antara lain ikan, udang, kepiting, moluska dan polychaeta. Tujuan penelitian ini adalah untuk mengetahui distribusi dan kelimpahan polychaeta di daerah Klaces dan Sapuregel yang memiliki perbedaan tingkat sedimentasi. Hasil penelitian telah ditemukan 20 famili polychaeta, 5 famili di Klaces dengan kelimpahan 44,68 ind/ m2 dan 17 famili di Sapuregel dengan kelimpahan 88,38 ind/m2. Biomassa untuk 4 famili yang dominan di kedua lokasi penelitian tidak memiliki perbedaan yang signifikan kecuali pada famili Capitellidae yaitu 0,026 g/ind di Klaces dan di Sapuregel 0,012 g/ind. Indeks keanekaragaman (H’) di Klaces dan Sapuregel masing-masing adalah 0,49 (keanekaragaman famili rendah) dan 1,11 (keanekaragaman famili sedang), serta indeks keragamannya (e) 0,27 dan 0,30 (keseragamanfamili rendah). Indeks dominasi (C) di Klaces 0,64 (terdapat famili yang mendominasi) lebih besar dariSapuregel yaitu 0,33(tidak terdapat famili yang mendominasi).Kata kunci : polychaeta, distribusi, kelimpahan, mangroveThe high productivity in mangrove area has ecological function which is important for other living organisms, among others is for spawning area, nursery and feeding area. The biota which is live in mangrove ecological system are fish, shrimp, crab, mollusc, and polychaeta. The objective of this research is to look for the distribution and abundance of polychaeta in Klaces and Sapuregel area where are have difference sedimentation level. Twenty polychaeta families were found in this research, 5 families in Klaces and 17 families in Sapuregel. Abundance of polychaeta in Klaces was 44,68 ind/m2, this was fewer than in Sapuregel. The biomass for 4 families which was dominant in two research area were not have significant different, except Capitellidae. Biomass Capitellidae was 0,026 g/ind in Klaces and 0,012 g/ind in Sapuregel. Diversity Index (H’) in each research area Klaces and Sapuregel were 0,49 (low diversitylevel) and 1,11 (moderate diversity level) with evenness index (e) 0,27 and 0,3 (low evenness indexlevel). Domination index (C) in Klaces was 0,64 and in Sapuregel was 0,23. This value shows thatdomination index Klaces was more than Sapuregel.Key words : polychaeta, distribution, abundance, mangrove