Plastic debris has a long-term and quite severe impact on the marine ecosystem. Population growth in the developing area, Makassar coastal zone, will contribute significantly to the land’s waste. Consequently, floating plastic debris comes directly from the land’s plastic leaks to rapidly increase marine plastic debris. Due to being a major environmental issue in the coastal zone and reducing options for removal are very limited, this study becomes to detect the potential marine plastic debris in Makassar by Sentinel-2 Multi-Spectral Instrument (MSI) using Kernel Normalization Vegetation Index (KNDVI) and Floating Debris Index (FDI) for satellite image processing. The plastic debris was corrected atmospheric effect by Sen2Cor and processed by Sentinel Application Platform (SNAP). The resolution of images was set to 10 x 10 meters. The target area was calculated as 173.47 Ha. The results show that KNDVI and FDI combined are a developed and powerful approach to detecting plastic debris. KNDVI has more representative indices (SE 0.38) than FDI indices (SE 0.47). Through the discriminant analysis were verified pixels of KNDVI (3506 pixels) and FDI indices (701 pixels). Meanwhile, the Sensitivity Analysis Value (SAV) was well performed to detect the potential of marine plastic debris by KNDVI with SAV 7.5 than FDI indices with SAV 2.9.