Indonesia is a country located on the Pacific Ring of Fire which causes Indonesia to have the largest number of active volcanoes in the world, resulting in frequent volcanic eruptions. As happened in 2021, the eruption of Semeru Volcano caused casualties and damage to landuse. This study aims to determine the impact of the 2021 Semeru Volcano Eruption and to map the impact of Semeru Volcano erupton to landuse in Lumajang Regency using Normalized Difference Vegetation Index (NDVI). This research includes three stages. In the first stage, data collection was carried out by downloading pre-eruption and post-eruption Landsat 8 OLI satellite images of Semeru Volcano. Second, analyze data, reports and documents to obtain data and information regarding the impact of the Semeru Volcano eruption. The third phase focuses on data analysis and mapping of impact caused by the eruption. The most affected area with lahar flood were bareland with 2330 ha or 45.56% of affected area, followed by forest with 1921 ha (37.56%), dryland agriculture with 713 ha (13.94%) and rice fields with 134 ha (2.62%). The whole area that affected by Semeru Volcano eruption in Lumajang Regency is 5114 ha or 2.8% from total area of Lumajang Regency. Pronojiwo District is the district with the largest area affected by the eruption with total of 20.34% of its area affected by Semeru Volcano eruption.