In water disinfection, the predominantly disinfectant used for drinking water is chlorine. The generation via reactions with natural organic matter (NOM) in chlorine disinfection of drinking water consequently results the formation of disinfection by-products (DBP). The paramount of these DBPs, are haloacetic acids (HAA) that have different factors touching their concentrations, which are, bromide concentration, pH, temperature, free chlorine dose, contact time and NOM. However, their formation mechanisms are still being searched. In this research, we developed a multivariate linear regression model of analysis based on the use of water quality parameter in order to predict the concentrations of different compounds of HAA5 and total HAA5. The effects of pH, free-Cl2 and NOM level on yields as well as the speciation of HAA in chlorinated water are studied. The results of this investigation showed that the obtained experimental water quality parameter data presented average value that are; pH= 7.25, free-Cl2= 2.84, UV254=0.16. A strong relationship between HAA formation and the studied water quality parameter was revealed to be R2>0.885. The regression coefficient R2 values of the established models varied between 0.70 and 0.97, indicated an excellent predictive aptitude for water quality parameters and HAA5 in drinking water. The obtained statistical evaluation indicates that under the measurements of pH, chlorine dose and UV254 values, the formation of HAA5 in water can be described by the multiple linear regression technique. Moreover, these Contaminants Modeling are relevant for the study of human health effects through the exposure to DBPs and taking in consideration that the consumed water was collected from different resources with different properties.