Quantitative structure–activity relationship (QSAR) modeling is an important part of chemical/biological data analysis and chemoinformatics. The low cost and high speed of screening of large chemical databases, make the QSAR analysis more efficient than the experimental methods. The linear and multi-linear regression models are extensively used for predicting biological/ecotoxicological activities or properties. Various conceptual density functional theory (CDFT) and information theory-based (IT) descriptors are used to develop the QSAR models. In this regard, different experimental toxicity parameters are considered as the dependent variable, whereas some CDFT descriptors are used as the independent variables. On the other hand, IT descriptors are also used to develop the QSAR model for describing different structural parameters and properties of the chemical systems.