Diploma thesis entitled 'Evaluation of erosion control function of riparian vegetation streams Hájský potok (Slovak Karst) with method BEHI (BANK EROSION HAZARD INDEX) deals with the issues of soil erosion in the study area of Slovak Karst National Park. The introductory chapter is briefly characterized by issues of soil erosion with an emphasis on water erosion. Following the theoretical knowledge, the core of diploma thesis is dedicated to the analysis and assessment of anti-erosion features of riparian vegetation on the section of Hájske stream under investigation. The final chapter is devoted to draft of anti-erosion measures in the study area based on the detected results of the measurements made in outdoor.