Abstract. Research on analysis of sediments chemistry around the mangrove ecosystem of Lambadeuk village, Peukan Bada Subdistrict aimed to the analyze nutrient content of sediments around mangrove ecosystem which grows in Lambadeuk, Aceh Besar. The study was conducted in April 2018 - May 2019. Research stations were determined by using purposive random sampling method then sediment samples were taken by coring technic. The results of the analysis showed that there are two types of sediments; muddy sand and sandy mud type of sediment. Sandy mud sediment has higher organic matter than muddy sand. The percentage value of total organic matters ranged from 27.89% - 42.41%, while C-Organic was between 0.08% - 1.28%. The percentage of dominant C-organic was found in places that are overgrown with mangroves, while the total organic matter content is more in places that does not have mangroves. In addition to the presence of mangroves that affect the amount of organic sediment and type of sediment, oceanographic factors such as currents, topography, organic matter content, and C-Organic are also affect the type of existing sediment.Keywords: Mangroves, Sediment, Organic matter, C-Organic.Abstrak. Penelitian mengenai analisis kimia sedimen di sekitar ekosistem mangrove Desa Lambadeuk, Kecamatan Peukan Bada bertujuan untuk menganalisis kandungan unsur hara sedimen di sekitar ekosistem mangrove yang tumbuh di daerah Lambadeuk, Aceh Besar. Penelitian ini dilakukan pada bulan April – Mei 2019. Metode penentuan stasiun penelitian menggunakan metode purposive random sampling kemudian sampel sedimen diambil dengan menggunakan coring. Hasil analisis menunjukkan bahwa tipe sedimen yang ada di Desa Lambadeuk, Kecamatan Peukan Bada terdapat dua tipe sedimen yaitu pasir berlumpur (muddy sand) dan lumpur berpasir (sandy mud). Tipe sedimen lumpur berpasir memiliki kandungan bahan organik lebih tinggi daripada pasir berlumpur. Nilai persentase kandungan bahan organik total berkisar yaitu berkisar antara 27,89 % - 42,41 %, sedangkan C-organik berkisar antara 0,08 % - 1,28 %. Persentase C-organik lebih banyak terdapat di tempat yang banyak ditumbuhi mangrove, sedangkan kandungan bahan organik total lebih banyak di tempat yang tidak ditumbuhi mangrove sama sekali. Disamping keberadaan mangrove yang mempengaruhi besarnya bahan organic sedimen, faktor-faktor oseanografi seperti arus, topografi, kandungan bahan organik, dan C-organik juga mempengauhi tipe sedimen yang ada.Kata Kunci: Mangrove, Sedimen, Bahan Organik, C-organik.