Drought stress is one of the main abiotic stresses that has negative effect on bean production and causes yield reduction, and significantly affects the process of photosynthesis. Measurement of chlorophyll fluorescence is a common method of determining the reaction of plants under stress conditions. Chlorophyll fluorescence analysis is a fast, non-invasive, and relatively simple method, and provides detailed information on the state of Photosystem II (PSII) under stress conditions. The aim of this study is to determine the influence of drought stress on photosynthesis light reactions and differences in drought stress tolerance in Croatian common bean landraces using measurements of chlorophyll fluorescence. Five bean genotypes exposed to drought stress with the addition of polyethylene glycol (PEG) were used in the experiment. The CropReporter imaging and analysis system was used to measure chlorophyll fluorescence, and the parameters Fv / Fm, Fq '/ Fm', ETR, NPQ and qP were analyzed. Data were statistically processed by R software (R Core Team, 2019) using a general linear model. The results of the study showed that the parameters Fq '/ Fm', ETR, NPQ and qP changed significantly under the influence of drought stress, while the parameter Fv / Fm was less sensitive. Significant changes in the measured parameters in plants under drought stress showed chlorophyll fluorescence as a suitable method for the research of drought tolerant common bean genotypes.