Rice is one of the main crops in the U.A.R. especially in fertile soils. Cultivation of rice in such soils is expected to change the normal microflora ; a matter which may affect their fertility. It is expected that water-logging will promote the growth of anaerobic microflora. These are well known to cause undesirable processes in the soil such as nitrate reduction, denitrification and sulphate reduction. It will also dilute soil nutrients, cause the leaching of salts and change the form of organic matter in the soil. Therefore, the study of microbiology and chemistry of paddy soil will be of great importance, especially it has not been tackled before in the U.A.R. This study will throw light on the microbial development under water-logged conditions, enabling us to know the microbial equilibrium and to justify the soil conditions after being dried and prepared for the next crop.