This study was conducted to analyze the effect of probiotic application in water media on the growth and survival of vannamei shrimp. It also aimed to determine the optimal probiotic dosage for enhancing growth and survival. The research was carried out for 45 days using a Completely Randomized Design (CRD). The treatments included different probiotic dosages: Treatment A = addition of Lactobacillus sp. at 2.0 ml/L, Treatment B = 2.5 ml/L, and Treatment C = 3.0 ml/L. Data were analyzed using ANOVA through the SPSS application. The observed parameters during the study included length growth, weight gain, and survival rate. Based on probiotic bacteria testing conducted at the Microbiology Laboratory, Faculty of Mathematics and Natural Sciences, Universitas Negeri Gorontalo (UNG), the probiotic developed through fermentation showed bacterial growth identified as Lactobacillus, with a total colony count of 1.23 × 10⁸ CFU/ml. The results indicated that Treatment C (Lactobacillus sp. 3.0 ml/L) provided the best growth performance, with weight gain of 0.23 g and length growth of 1.02 cm. Meanwhile, the highest survival rate was found in Treatment B (Lactobacillus sp. 2.5 ml/L), at 54%. According to the ANOVA results, different probiotic dosages of Lactobacillus sp. had a significant effect on length growth but showed no significant effect on weight gain and survival of vannamei shrimp. Keywords: Vannamei shrimp, Lactobacillus sp., growth, survival rate Abstrak. Penelitian ini dilaksanakan bertujuan untuk menganalisis pengaruh pemberian probiotik pada media air terhadap pertumbuhan dan kelangsungan hidup udang vaname. Serta menganalisis dosis terbaik pemberian probiotik terhadap pertumbuhan dan kelangsungan hidup udang vaname. Penelitian dilakukan selama 45 hari menggunakan Rancangan Acak Lengkap (RAL). Dengan pemberian dosis yang berbeda perlakuan A = Penambahan probiotik Lactobacillus sp. 2,0 ml/l, perlakuan B = Penambahan probiotik Lactobacillussp.2,5 ml/l, Perlakuan C = Penambahan probiotik Lactobacillussp.3,0 ml/l. Analisis data yang digunakan yaitu ANOVA dengan menggunakan aplikasi SPSS. Parameter yang diamati selama penelitian yaitu pertumbuhan panjang, berat, tingkat kelangsungan hidup. Berdasarkan hasil pengujian bakteri probiotik yang dilakukan di Laboratorium Mikrobiologi, Fakultas MIPA, UNG, menunjukkan adanya bakteri yang tumbuh dari probiotik yang dibuat dengan cara fermentasi, memperoleh jenis bakteri Lactobacillus dengan perhitungan total koloni yang diperoleh yaitu 1,23 × 10^8 CFU/ml. Hasil penelitian menunjukkan perlakuan C (probiotik Lactobacillus sp.3,0 ml/l) memberikan hasil pertumbuhan yang terbaik, yaitu pertumbuhan berat = 0,23 g, pertumbuhan panjang = 1,02 cm. Sedangkan tingkat kelangsungan hidup yang terbaik terdapat pada perlakuan B (probiotik Lactobacillus sp.2,5 ml/l) yaitu 54%. Berdasarkan hasil ANOVA, pemberian probiotik Lactobacillus sp. yang berbeda memberikan pengaruh berbeda nyata terhadap pertumbuhan panjang, namun tidak berbeda nyata terhadap pertumbuhan berat dan kelangsungan hidup udang vaname. Kata Kunci: Udang vaname, lactobacillus Sp, pertumbuhan, kelangsungan hidup