Pathogen Plasmopara halstedii causes low seed yield at sunflower genotypes, in year with high precipitation and low temperature in first stage of development of sunflower plant. In year 2021, at Fundulea location, sunflower downy mildew has a big attack degree of infection in first stage of development, due to weather conditions and in year 2022, degree attack was very low. In year 2021, only differential line for downy mildew HA 288 (gene Pl??) from Institute of Field and Vegetable Crops Novi Sad, Serbia and differential lines RHA419 (gene PlArg), accession Pl 619204 and HA-R5 (gene Pl13), accession Pl 650763 from United States National Plant Germplasm System, has 0% attack degree of pathogen Plasmopara halstedii. In year 2022, only differential line for downy mildew RHA274(gene Pl2/Pl21), accession Pl 599759, from United States National Plant Germplasm System and differential lines DM 2 93CA from Institute of Field and Vegetable Crops Novi Sad, Serbia and RHA340 (gene Pl8), HA 335 (gene Pl6), has sunflower plant infected with pathogen Plasmopara halstedii. Year 2021 was the reference for selection of resistant sunflower genotypes at downy mildew. In year 2021, in Fundulea location, only three sunflower genotypes created at NARDI Fundulea, SPL 21-2X Helianthus maximiliani (F2 generation), SPL 14-3 and 17-3 P. sint, was resistant at races of downy mildew present in this area. These three sunflower genotypes represent sources of resistance at pathogen Plasmopara halstedii.