A novel method was applied to study the topological and molecular structures of multicomponent rubber. This method is based on the thermomechanical analysis of a solid polymer. A diblock amorphous structure was found for the studied rubber network. These blocks differ a great deal in their glass transition temperature. The methodology of how to calculate the crosslink density in each block, the molecular weight distribution of the chains between the junctions of the network, and the shares of low-temperature (soft) and high-temperature (hard) blocks in a structure of the rubber network were also shown. Based on these data it; is possible to calculate the number-average and weight-average molecular weight and the polydispersity coefficients of the chains between the junctions of the network.