The paper deals with all of important materials parameters which are required for computational modeling in relation to the specific composites where the matrix is represented by elastomeric material. In the given paper, the mentioned materials parametres have to be used as input data to make the computational model of the radial car tire. The composite structures in the car tire are required to be described by help of appropriate parametres while the given parametres include geometric arrangement of reinforcements in the elastomeric matrix. The main attention is paid to the steel-cord belt. There are some ways how to replace the steel-cord belt. In this paper, the authors pay their attention to the orthotropic material which is often used as a replacement of steel-cord belt because the given orthotropic material has quite good response to the surrounding environment. After the determination of the input parametres, it is necessary to perform some experimental tests which has to be completed by microscopic observation and by this way, the more detailed information can be obtained in relation to the arrangement of the reinforcements in the area under the tread.