Haloacetic acids (HAA) and Trihalomethanes (THM) are found in large amount as disinfection by-products (DBPs) in finished drinking waters. Conventionally, THM have been used as surrogates for DBP. The aim of this present study is to consist a portrait and a model of spatial-temporal formation of HAA as a function of THM species combination in drinking water samples from Tunisia districts. The analysis of HAA and THM and other physico-chemical parameters were accomplished into a six-month sampling program.Also, The occurrence of these DBP depending on seasonal variation reflects very different DBP amounts and the concentrations of HAA are between 19 and 115 μg.L-1 while these of THM are between 46–123 μg.L-1. Statistical correlations between HAAs and THMs were developed and statistically significant correlation between total THM and HAA were found (Pearson's correlation coefficient, 0.955