Abstrak: Bivalvia merupakan anggota kelas moluska yang memiliki nilai ekonomis dan menjadikannya sering dieksploitasi berlebih oleh masyarakat. Penelitian ini bertujuan untuk mengetahui indeks keanekaragaman dan kelimpahan bivalvia di Perairan Pantai Waemulang Kabupaten Buru Selatan. Pengambilan sampel dilakukan pada kondisi air surut dengan menggunakan metode transek linear kuadrat yang disesuaikan dengan luas area Perairan Pantai Waemulang, panjang garis pantai dan relif pantai. Disamping itu, dilakukan pula pengukuran parameter fisik kimia lingkungan sebagai data pendukung. Hasil penelitian menunjukkan bahwa bivalvia yang ditemukan terdiri dari 5 Ordo, 5 Family, 6 Genus, dan 7 Spesies, yakni Anadara antiquata, Gafrarium dispar, Modiolus modiolus, Fragum unedo, Pinna bicolor, Anadara granosa, dan Tapes literatus. Nilai kelimpahan tertinggi terdapat pada spesies Anadara antiquata, yakni 5.495 dan kelimpahan relatifnya 16.22%. Sedangkan nilai kelimpahan terrendah terdapat pada spesies Tapes literatus, yakni 4.272, dan kelimpahan relatifnya 12.61%. Nilai indeks keanekaragaman, yakni 1.93 atau termasuk kategori sedang dan indeks dominansi sebesar 0.14 yang menunjukkan tidak ada dominansi spesies. Hasil pengukuran parameter fisik kimia pun masih berada dalam kisaran optimal sesuai dengan standar baku mutu air laut untuk biota laut. Guna pemanfaatan dan pengelolaan bivalvia secara berkelanjutan di Perairan Pantai Waemulang Kabupaten Buru Selatan maka diperlukan penelitian sejenis secara berkala.Kata Kunci: Bivalvia, Keanekaragaman, Kelimpahan, Waemulang. Bivalves is a member of the mollusk class with economic value and makes it often over exploited by the community. This study aims to determine the diversity index and abundance of bivalves in the Waemulang Coastal Waters of South Buru Regency. Sampling is done at low tide conditions using the linear quadratic transect method that is adjusted to the area of Waemulang Coastal Waters, coastline length and coastline. Besides that, physical chemical parameters were also measured as supporting data. The results showed that bivalves were found to consist of 5 Orders, 5 Families, 6 Genera, and 7 Species, namely Anadara antiquata, Gafrarium dispar, Modiolus modiolus, Fragum unedo, Pinna bicolor, Anadara granosa, and Tapes literatus. The highest abundance was found in Anadara antiquata, which was 5,495 and its relative abundance was 16.22%. While the lowest abundance was found in Tapes literatus, which was 4.272, and the relative abundance was 12.61%. Diversity index value is 1.93 or including a medium category and dominance index of 0.14 which shows no species dominance. The results of the measurement of physical chemical parameters are still in the optimal range in accordance with sea water quality standards for marine biota. For the sustainable use and management of bivalves in the Waemulang Coastal Waters, South Buru Regency, regular research is needed.Keywords: Bivalves, Diversity, Abundance, Waemulang.