This research aims to study weeds diversity among five represented habitats namely; field crops, orchards, canal banks, wastelands and water bodies along Mariotteya Canal, Giza. A total of 88 species belong to 74 genera and 27 families were recorded and identified with Egyptian floras and available checklists. The dicotyledons families were represented by (69%); while monocotyledons were (31%). The common families were Poaceae (26%); while both of Compositae and Leguminosae were represented by (8%). Three species were recorded from each of Apiaceae, Cyperaceae, Malvaceae and Polygonaceae and two species from Salicaceae and Amaranthaceae. In addition to, 13 families were monotypic. The annuals species were represented by (59%), perennial herbs were (30%); while trees, shrubs and biennials species were (7%), (3%) and (1%); respectively. The life form showed that, therophytes species were represented by (60%) followed by chamaephytes (14%) then phanerophytes (10%). The chorological ratios showed that cosmopolitan taxa had the highest contribution (25%), followed by pantropical (19%) then palaeotropical (14%). Based on species recorded among five represented habitats, the cluster analysis divided the studied habitats into three groups. Group one included field crops and orchards habitats. Second group contained canal banks and wastelands habitats; while third group included water bodies' habitat. Moreover, field crops and orchards habitats showed the highest similarity value (0.614) followed by (0.559) between canal banks and wastelands habitats. On the other hand, there was no similarity between species of water bodies' habitat and species of the other habitats.