Abstract: The main problem in the hatchery of tilapia (Oreochromis niloticus) is the low survival rate, especially in the larval to juvenile stages. One of the causes of the low survival rate is caused by the digestive organs of the larvae themselves which are still not perfect to digest the artificial feed given. This study aims to determine the optimum dose of the probiotic in rearing the best tilapia larvae. The study was carried out at the Aquatic UMK Fish Nursery Unit Widya, Tamalanrea, Makassar using a 30 L capacity green plastic basin filled with 25 L of media water. The test animals used were Tilapia larvae aged 7 days and kept for 30 days.