Aims: The object of the study was to identify chlorine demand factorsin water and chlorine in Kanbebein City water and eliminating of them. Materials and Methods: Concentration of free and combined residual chlorine with the methods presented in the book "Standard Methods for Water and Wastewater Examination" were measured. Other parameters such as: Temperature, TOC, TDS, pH, EC, nitrate, ammonia, total hardness, alkalinity, iron and manganese were also examined before and after of chlorination. Results: The Highest chlorine decay constant in the short time were in water well was 0.895 mgL -1 h -1 and the least amount of it was 0.0097 mgL -1 h -1 and the Highest chlorine decay constant in the long time were in water well was-0.092Lmg -1 h -1 and the least amount of it was-0.0017 Lmg -1 h -1 that correlated with nitrite, ammonia and iron concentration. Conclusion: The factors that affected short-time chlorine decay constant (k 2 ) were nitrite, ammonia and iron and The factors that affected on long-time chlorine decay constant (k 2 ) were Nitrite, ammonia and iron. The material removal techniques for them were the use of natural resins, zeolite, ion exchange, membrane and aeration methods, oxidation and sedimentation, and filtration.