Amorpha fruticosa is a species of flowering plant in the legume family (Fabaceae) known by several common names, including desert false indigo, false indigo-bush, and bastard indigobush. It originates from North America, being brought into Europe through England in 1724. In the beginning of the 19th century, it began to spread to Croatia from Hungary, and nowadays has a status of invasive species. The purpose of this work was to find out efficient ways of how to monitor the false indigo-bush in Lonjsko polje Nature park. To test the possibility of monitoring it by remote sensing techniques, I used Landsat satellite images from 2000, 2006 and 2017. As a reference map, I used the 2006 habitat map of the Lonjsko Polje Nature Park. On the habitat reference map, I tested the accuracy of the controlled classification (MAXLIKE) of satellite imagery, the NDVI (Normalized Difference Vegetation Index), and the spectral signature of Amorpha stands through all channels of 30-meter spatial resolution. I did the procedures of controlled classification, NDVI and spectral signatures of Amorpha using IDRISI, QGis and SAGA programs.The most accurate was the spectral signature method which, unlike the NDVI index that represents the ratio of two spectral channels, uses 5 spectral channels in the visible and near-infrared part of the spectrum. Predicted areas covered with indigo bush (including combination with other habitat types) continuously increased from 12.9 % in year 2000, 45 % in 2006 and 58 % in 2017. However, these areas contained significant misclassified areas covered with ash and pedunculate oak stands. To obtain greater accuracy using Landsat satellite imagery, it would be necessary to use images from multiple periods during the growing season, which could increase the distinction of Amorpha stands from younger stands of ash and pedunculate oak forests and increase their applicability in monitoring Amorpha spreading.