Alnajmi Agricultural project, Muthanna, Iraq, featured with wide salt affected soils, although it is considered as a significant project for irrigated agriculture. Salt affected soils in this project were studied in different methodologies. Micromorphology descriptive study was conducted to get more information about the salinization process in this project. Eight pedons out of twenty-five ones were selected to be examined micromorphologically. Six of these pedons were salt affected, while the other two were none salt affected soils. As a comparison among those eight pedons, saline soils showed different features related to microstructure and porosity, besides coatings as salwans (salt cutans) and calcitans (carbonate cutans). Paleosalinization process showed clear salwans in examined soils, while recently salinized soils showed weak features of salt coatings. Carbonate coatings were found in all samples due to the nature of the soil formation in arid and semi-arid regions. None salt affected soils did not show salt coatings, while they showed carbonate minerals coatings.