North Sinai environment is currently subjected to changes due to the major agricultural development project of El-Salam canal which brings Nile water to the arid deserts of Sinai. Therefore, intensive efforts are made to record biodiversity of natural microflora and diazotrophs associated to the plant - soil system of the major agricultural development areas around the canal. Fourteen soil profiles were made, during the seasons 1997 - 2000, representing major sites of the area investigated (South Qantara, Rabaa-Bir El-Abd and El-Ser and Al-Quarir). Physico-chemical and microbiological properties of soils tested are presented. Microbiological profiling included total population of Gram positive and Gram negative bacteria, sporeformers, thermophiles, diazotrophs and spore-forming diazotrophs. Results obtained are discussed to relate physico-chemical properties to soil biofertility in an effort to categorize general fertility levels of soils under investigation.