The work dealing with the wetlands of the Oranie are few and that studying the Floristic cortege is even rarer. Among the wetlands of the west Algeria, that of the Macta, remains one of the most interesting areas to study.

The Macta, is constituted by a rich ecosystem and specific. It is characterized by the presence of water during almost the entire year, by a diverse wildlife and by vegetation subservient (vegetation halophyte). Of this fact, it is a site where the protection and the preservation of this biological diversity is more than necessary on both the national and international level.

In terms of climate, the exploitation of Weather Data Highlights average elevation of the temperature of 1.5°C and a decrease of the tranche of rainfall annual average, with impacts on the floristic composition of this space.

The pedological approach confirms the clayey texture of the ground where the majority of the surveys have been carried out. In addition, the electrical conductivity shows the saline character of the soil, with an alkaline pH.

The floristic study has made it possible to Inventory 83 species say halophytes to broad distribution and abundance high enough. Among the halophytic species, include Sarcocornia fruticosa, Atriplex halimus... We also note the presence of species of land uncultivated and brownfield sites, as well as some of the introduced species by reforestation as Pinus halepensis, Acacia horrida,...

The statistical study, through a factorial analysis of correspondences (AFC) has helped to establish a correlation between the vegetation and environmental factors studied. The vegetative mat of the Macta wetland rest conditioning, in addition to the climate, by the edaphic factor and by the time and the intensity of flooding by the water.

Key words: wetland – biodiversity - Climate - Soil - halophilic vegetation- western Algeria