Ethanol­-water liquid mixture was analyzed by the method of Molecular Dynamics, over the whole composition range to elucidate its micro structure. A recently introduced concept of microheterogeneity was used to describe mixture's behaviour. It was discovered that there are at least three structural regimes with respect to composition range in aqueous ethanol at ambient conditions. Up to approximately 0.15 mole fraction of ethanol, hydrophobic ethanol's sites distribution declines from homogenous. From 0.15 to approximately 0.65 mole fraction of ethanol, ethanol and water form bi­continuous intertwined microheterogenous mixture of segregated domains, and above 0.65 mole fraction of ethanol water network loses its connectivity over the whole system. Results from the novel approach in cluster analysis, performed for the first time on this kind of system, namely the calculation of cluster radial distribution function, were especially important for supporting the picture of three structural regimes. This is the first time that such detailed overall picture of the microscopic level structure of this liquid mixture is given. Besides, in­-detail analysis of different ethanol models in their ability to reproduce this structural change with mole fraction is presented; models that are parametrized on pure substance thermodynamical properties, as well as one model parametrized on the solute activity in the aqueous mixture.