Wetland systems in arid countries can serve as a rich source of biodiversity and an ideal location to study invertebrate species diversity. Two study sites have been delimited in the Chott Zahrez Gharbi characterised by a semi-arid climate, a cold winter and a vegetation cover dominated by halophile species. One site is located north of Zahrez in the Hassi Bahbah region and the second one south of Zahrez in the Zaâfrane region. A comparative study of the Arthropoda communities, focused on Coleoptera and Araneae, was conducted during one year, using pitfall traps (Barber traps) monthly. In total 7344 individuals, belonging to 215 species, including 80 species of Coleoptera and 38 species of Araneae were collected. The Shannon-Weaver diversity index (H') varies between 0.41 and 2.95 bits. The results showed that Hassi Bahbah is richer and more diverse than Zaâfrane. The humidity and the organic matter are clearly higher in Hassi Bahbah than in Zaâfrane. A detrended correspondence analysis (DCA) showed a clear distinction of the species' groups between the two study areas.