ABSTRAK Telah dilakukan penelitian tentang terumbu karang di wilayah pesisir Kabupaten Aceh Besar pada bulan September 2012 sampai dengan bulan Februari 2013. Tujuan penelitian ini adalah untuk mengetahui kondisi keragaman bentuk hidup (lifeform) terumbu karang. Pengambilan data dilakukan pada 8 titik lokasi, yakni Amat Aramanyang, Lhok Keutapang, Pulau Di tuan, Lampuuk, Lhok Seudu, Leupung, Pulo Aceh, dan Lamteng. Metode yang digunakan pada penelitian ini adalah metode Line Intercept Transect (LIT). Transek di pasang sepanjang 70 meter dengan penempatan sejajar dengan garis pantai. Pengambilan data dilakukan pada dua kedalaman, masing-masing kedalaman 3-4 meter dan kedalaman 6-8 meter. Pencatatan data dilakukan dengan tiga kali pengulangan dengan interval 5 meter. Hasil penelitian menunjukkan bahwa persentase tutupan karang pada kedalaman 3-4 meter berkisar antara 33,25% - 65,30% dengan tutupan rata-ratanya adalah 50,74%, dan 25,85% - 64,43% di kedalaman 6-8 meter dengan rata-rata persentase tutupan karangnya adalah 48,21%. Persentase lifeform terumbu karang pada kedalaman 3-4 meter di dominasi oleh lifeform ACT (15,05%), CM (14,89%), dan ACB (11,68%), dan di kedalaman 6-8 meter di dominasi oleh lifeform ACB (11,82%), CM (10,23%), dan ACT ( 9,85%). Kata kunci : terumbu karang, lifeform karang, keragaman, Aceh Besar. ABSTRACT The research about condition of coral reefs has been done in the coastal areas of Aceh Besar districts from September 2012 to February 2013. The purpose of this study was to determined the condition of the diversity of lifeforms coral reefs. Data collection was performed at 8 point locations, that was Amat Aramanyang, Lhok Keutapang, Pulau Di tuan, Lampuuk, Lhok Seudu, Leupung, Pulo Aceh, and Lamteng. The method used in this study was the method of Line Intercept Transect (LIT). Transects in pairs along the 70 meter by placing parallel to the shoreline. Data collections were taking at two depths, 3-4 meter 6-8 meter. Data recording was taken with three repetitions at interval of 5 meter. The results showed that the percentage of coral cover at depth of 3-4 meter ranged from 33.25% - 65.30% with the average was 50.74%, and 25.85% - 64.43% at 6-8 meter with average percentage was 48.21%. Percentage lifeform coral reefs at depth of 3-4 meter was dominated by lifeform ACT (15.05%), CM (14.89%), and ACB (11.68%), and depth of 6-8 meter was dominated by lifeform ACB (11.82%), CM (10.23%), and ACT ( 9.85%). Keywords: coral reefs, coral lifeform, diversity, Aceh Besar.