Nowadays postharvest loss of grains due to storage system is a critical issue especially in sub Saharan African countries. As it is stated in some literature the cost of food lost in post-harvest due to storage is much greater than the aid donated by developed countries to those sub Saharan countries. One of the main reasons for the loss is the storage culture, changing this culture by developing scientific and easily adoptable system like hermetically sealed storage system have significant impact on food security, economy and environmental protection. It is known that the storage effectiveness of grain storage system is highly dependent on temperature, gas and moisture distribution characteristics inside storage system. The aim of this project was to study gas and moisture distribution characteristics of hermetically sealed grain storage system and compare the characteristics of hermetically sealed system with conventional polypropylene bag with interaction of its surrounding environment using Experimental design software. The study was validated using experimental results, distributions of oxygen, carbon dioxide and moisture inside the storage system was investigated. The effects of thickness, storage time, RH and temperature on the permeability of storage structure was studied. In this study work, it was found that the permeability of the storage structure was mainly affected with the material thickness, as the material thickness increased the permeability decreases. The transmission rate of moisture vapor is mainly affected by relative humidity of the environment, thickness of the material and temperature of the environment. Concentration of CO2 % for poly bag was very low the mean value was 0.333% whereas the hermetic was 1.066%. The same trend was observed for moisture vapor transmission rate (MVTR) the higher value was that of conventional poly bag which is 1.18 g*mm/M 2*d, hermetic bag 0.891 g*mm/M 2 *d. Keywords- Studying, Characteristics, Experimental, hermetic, Grain, Storage systems