ABSTRAK Telah dilakukan penelitian yang bertujuan untuk menganalisis keanekaragaman jenis makrozoobentos di perairan Sungai Krueng Sabee, Kabupaten Aceh Jaya, Provinsi Aceh. Pengambilan sampel dilakukan dengan Purposive Sampling pada 6 stasiun pengamatan. Stasiun penelitian ditentukan mulai dari hulu sungai sampai hilir sungai. Parameter yang diamati dalam penelitian ini adalah parameter biologi (jumlah jenis dan jumlah individu masing-masing jenis makrozoobentos), parameter fisika (kecepatan arus, suhu air, dan substrat), dan parameter kimia (pH air, dissolved oxygen (DO), dan salinitas). Hasil penelitian diperoleh 25 spesies makrozoobentos yang tergolong ke dalam filum Moluska (Gastropoda 6 spesies) dan Bivalvia 6 spesies) dan filum Arthropoda (Insekta 1 spesies dan Malacostraca 12 spesies). Nilai Indeks Keanekaragaman (H’) makrozoobentos yang diperoleh berkisar antara 1,750-2,508. Indeks Dominansi (C) makrozoobentos berkisar antara 0,090-0,196. Nilai Indeks similaritas makrozoobentos berkisar antara 0%-96%. Kondisi perairan Sungai Krueng Sabee masih sesuai untuk mendukung kehidupan makrozoobentos. Kata kunci : Makrozoobentos, Keanekaragaman, Sungai Krueng Sabee. ABSTRACT The research has been conducted which aims to analyze the species of macrozoobenthos in the Krueng Sabee River, Aceh Jaya Regency, Aceh Province. Samplings were conducted using descriptive method with purposive sampling technique at 6 observation stations. The research stations were determined from the upstream until downstream of the river. The parameters collected in this study are biological parameters (number of species, the number of individuals from each type of macrozoobenthos), physical parameters (current speed, water temperature, and substrate), chemical parameters (pH, dissolved oxygen (DO), and salinity). The results of this research were obtained 25 species of macrozoobenthos belonging to Phylum Mollusca (gastropods 6 species and bivalves 6 species), and Phylum Arthropoda (insects 1 species and malacostraca 12 species). The value of macrozoobenthos diversity index (H') is 1.750-2.508. The dominance index (C) value of macrozoobenthos shows a value of 0.09-0.196. The value of macrozoobenthos similarity index is 0%-96%. The climate conditions in the Krueng Sabee River are suitable for supporting macrozoobenthos life. Keywords: Makrozoobenthos, Diversity, Krueng Sabee River.