In the August 2019. on the area of Brodsko-posavska County, a survey was conducted on the first order lateral canal wild weed flora. Because of the frequent and intense rain fall in the area of Brodsko- posavska County, there have been constructed lateral canals. Weeds are a major problem of industrial sites, parks, under power lines, on railway lines, in the forests, then a long the path sand trails and in sports facilities. From the view point of the farmer, weeds are always harmful and unwanted plant species, whose presence reduces the quantity and quality of cultivated species. The aim of this study was to determine the species that make up the weed flora of the lateral canal „Biđ polja“. 15 species were determined, belonging to 12 families. According to the life form of all determined species, 64% were hemicryptophytes, 27% terophyte-hemicryptophytes, 5% geophytes, and 4% terophytes, and according to the floral element, Eurasians were the most represented with 73% (or 16 species), then sub-Central European ones with 9% (or 2 species), cosmopolites with 9% (or 2 species), sub-Mediterranean floral element with 5% and adventitious plants with 4%.