Generally, QSPR models are limited to individual compounds. In this thesis we have developed a QSPR approach to predict non-additive properties of binary mixtures, more explicitly their azeotropic behavior. To achieve this, several types of quantitative and qualitative models have been developed. This approach is original for two reasons. First, little research has been published on mixtures whose properties are no additive. Second, several new methodological aspects have been introduced in this work. First of all "special" descriptors able to describe mixtures have been proposed. In addition, a robust protocol for obtaining and validating models was used, and a reliable models applicability domain was proposed. The methodology developed during this thesis demonstrates the consistency of a new concept - the QSPR models for mixtures. It is comparable to other conventional methods, though using only limited data.