This study was carried out investigate the effect of long – term treatments with anhydrous ammonia on physicochemical properties of soil and soil micro flora. Soil samples were collected from different localities at fayom governorate. Results revealed that two soil texture were recorded being sandy clay soil for Hossam farms site and sandy clay loam soil for both of Rahil and Tamialocations .Soil of highest Rahil and Tamialocaties gave the values of EC . All tested soil collected from different localities were slightly alkaline . High percentage of Organic matter was detected at depth 15 -30 Cm of all sites treated with ammonia. The highest Sodium percentage was noticed at Tamia site. The highest amount of N and K  was recorded in soil collected form HossamNassar (10 years long –term ). The Total microbial count was recorded at the second depth (15 -30 Cm) than that observed at the first one. Total fungal counts recorded the highest values in soil Rahiland Tamia treated with ammonia - Asymbiaticaerbic nitrogen fixers showed high percentage at soil treated with urea . Clear retardation of harmful Nematodes was recorded in soil treated with ammonia at different sites and at different depths. Key Words: Anhydrous Ammonia, Physical and Chemical porpertes of soil , Micro flora, Nematodes.