Coral reefs are rich marine ecosystems that support a great degree of biodiversity. This is important for fish, with many fish species relying on coral reefs as their primary habitat. The current study aimed to analyze the variations of coral coverage and their relationship to fish abundance. This study was conducted in April 2019, in the waters of Samber Gelap Island, Kotabaru, South Kalimantan. The research used LIT (Line Intercept Transect) and UVC (Underwater Visual Census) methods to study coral coverage and fish abundance at 5 different stations, with each station having 3 transects of 50 meters in length. The results indicated that the highest coral coverage was station 5 (42.08%), which was classified as a fair category. This result was directly proportional to the abundance of coral reef fish at station 5 (781 individuals). In addition, the correlation test results between the effect of coral coverage and coral reef fish abundance showed a correlation value of 0.972. It was indicated that coral coverage had a strong influence on the abundance of coral reef fish in the waters of Samber Gelap Island, Kotabaru, South Kalimantan. The water conditions of Samber Gelap Island were classified as being supportive of coral reef life, except for current speed and brightness. In general, the percentage of coral cover in this location was categorized as being damaged, with the highest coverage found at station 5. In addition, station 5 also exhibited the highest number of coral reef fish abundance.