ABSTRAK Penelitian ini bertujuan menentukan tingkat salinitas yang optimum untuk pertumbuhan, kelangsungan hidup dan pemanfaatan pakan ikan kakap putih (Lates calcarifer). Penelitian ini dilakukan di Balai Perikanan Budidaya Air Payau (BPBAP) Ujung Batee pada bulan Oktober – Desember 2015 dan dilanjutkan di Laboratorium Terpadu Fakultas Pertanian, Universitas Syiah Kuala. Metode yang digunakan dalam penelitian ini adalah metode eksperimen dengan model Rancangan Acak Lengkap. Faktor yang diuji perlakuan salinitas 15, 18, 21, 24, 27, 30 dan 32 ppt. Pakan diberikan 2 kali sehari (08.00 dan 18.00 WIB) selama 60 hari. Hasil uji ANOVA menunjukkan bahwa perbedaan salinitas berpengaruh nyata terhadap pertambahan bobot mutlak, pertambahan panjang mutlak, laju pertumbuhan spesifik, laju pertumbuhan harian, rasio konversi pakan dan efesiensi pakan(P0.05) benih ikan kakap putih. Hasil penelitian menunjukkan bahwa pertambahan bobot berkisar antara 5.07 g – 8.66 g, pertumbuhan spesifik berkisar antara 1.48 % perhari – 1.93 % perhari, laju pertumbuhan harian berkisar antara 0.08 g/hari – 0.14 g/hari, rasio konversi pakan berkisar antara 1.80 – 1.43, efesiensi pakan berkisar antara 55.67 % - 70.04 % tingkat kelangsungan hidup berkisar antara 90.00 % - 93.33 % dan daya cerna protein berkisar antara 77.21 % – 81.98 %. Nilai tertinggi untuk semua parameter yang diukur didapatkan pada perlakuan A (15 ppt). Oleh karena itu disimpulkan salinitas 15 ppt adalah yang terbaik untuk ikan kakap putih. Kata Kunci : Ikan kakap putih, pertumbuhan, salinitas, tingkat kelangsungan hidup, rasio konversi pakan, daya cerna.   ABSTRACT The objective of the present study was to determine the optimum salinity for growth performance, survival rate and feed utilization of barramundi (Lates calcarifer). The study was conducted at Brackish Water Aquaculture Development Centre, Ujung Batee on October to December 2015 and at Laboratory of Agriculture Faculty, Syiah Kuala University. The Completely Randomized Design was used in this study, the tested salinity were 15, 18, 21, 24, 27, 30 and 32 ppt. The fish were fed two times a day at (08 PM and 06 PM) for 60 days. ANOVA test showed that the different salinity gave a significant effect on weight gain, specific growth rate, feed conversion ratio and feed efficiency (P 0.05). The results showed that weight gain ranged from 5.07 g to 8.66 g , specific growth rate ranged from 1.48 % day-1 to 1.93 % day-1, daily growth rate were 0.08 g day-1 – 0.14 g day-1, feed conversion ratio were 1.80 – 1.43, feed efficiency ranged between 55.67% - 70.04%, the survival rates were reached 93.33% and digestibility of protein ranged between 77.21 % – 81.98 %. The highest values for all measured parameters were obtained at treatment A (15 ppt). Therefore, it is concluded that the optimum salinity was 15 ppt for barramundi. Keywords: Lates calcarifer, growth, salinity, survival rate, feed conversion ratio, digesbility.