In November 2021, a study on the effect of mangrove density and maturity level on sediment trapping in the Langsa River estuary, Langsa City, was conducted with the objective of determining the density, maturity, and rate of sediment deposition around the mangrove forest, as well as the relationship between mangrove density and maturity level and sediment deposition rate. Mangrove vegetation was collected using a 40 m line transect parallel to the river flow and a 10 x 10 m plot, while sediment samples were collected using a sediment trap. The study's findings indicated that mangrove density varied between 675.00 and 1541.67 ind/ha, that mangrove maturity was uneven, with trunk diameters ranging between 4.14 and 9.83 cm and basal areas ranging between 30.45 and 72.93 m2/ha. Meanwhile, sediment deposition rates ranged between 26.94 and 277.73 mg/cm2/day, with a strong correlation between density and maturity of mangrove vegetation (98% and 99%, respectively).   Penelitian terhadap pengaruh tingkat kerapatan dan kedewasaan hutan mangrove dalam memerangkap sedimen di muara Sungai Langsa Kota Langsa dilakukan pada bulan November 2021 dengan tujuan untuk mengetahui tingkat kerapatan, kedewasaan dan laju pengendapan sedimen di sekitar hutan mangrovenya serta untuk mengetahui keterkaitan antara tingkat kerapatan dan kedewasaan hutan mangrove terhadap laju pengendapan sedimennya. Vegetasi mangrove dikumpulkan dengan menarik transek garis sepanjang 40 m yang sejajar dengan aliran sungai dan dibuat plot berukuran 10 x 10 m, sedangkan sampel sedimennya diambil menggunakan sediment trap. Hasil penelitian memperlihatkan bahwa kerapatan mangrovenya berkisar antara 675.00 – 1541.67 ind/ha, kedewasaan mangrovenya tidak merata dengan diameter batangnya berkisar antara 4.14 – 9.83 cm dan basal areanya berkisar antara 30.45 – 72.93 m2/ha. Sementara untuk laju pengendapan sedimennya berkisar antara 26.94 – 277.73 mg/cm2/hari, dimana keterkaitan antara kerapatan dan kedewasaan vegetasi mangrovenya memiliki hubungan yang kuat (masing-masing 98% dan 99%).