This study aims to determine the reproductive performance of Swamp buffalo with various dosage of gonadotropinreleasing hormone (GnRH). The study subjects were Swamp buffaloes (n=16) with an average age of about 5-6 years, a normal estrus cycle, non-pregnant, and had no history of reproductive disease. Estrus synchronization was performed with an injection of 5mL PGF2α hormone. GnRH was injected on the 8th day with various doses (A=without GnRH injection, B=200mg/2mL, C=300mg/3mL, and D=400mg/4mL). Variables observed were superovulation response, the success of artificial insemination, and speed and intensity of onset of estrus in Swamp buffalo. The results showed that the average superovulation response was 81.25%. The success rate of AI was on average 75% with the highest success rate (100%) with C treatment (300g GnRH + 5mL PGF2α). Swamp buffaloes that have been treated have onset of estrus ranging from 72-81hrs and high intensity of estrus. The administration of GnRH 300mg (group C) and 400mg (group D) gave the best superovulation response (100%) and a 100% pregnancy with the administration of 300mg of GnRH (group C). Administration of GnRH 200mg (group B) showed the fastest estrus onset and all treated buffaloes showed high estrus intensity with a score of +++.