Water quality of Rosetta Branch may be changed by several factors in the last decades as a result of anthropogenic activities. So, it's important to study water class along Rosetta Branch. This research focused on assessment surface water quality along  Rosetta Branch using Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI) supported by Egyptian guidelines of law 48/1982 decision 92/2013. Rosetta Branch received most pollutants from two hot spots namely: El-Rahawy drain and industrial activities in Kafr El-Zayat city. The water quality of eight sites-the main surface water resource for Delta Barrage, Edfina Barrage, Rahway, Sable, Tharir, Zawieyt El-bahr, Tala drains outfall and outlet of Rosetta Branch on Mediterranean Sea were investigated. The Geographic Information System (GIS) was used for mapping the WQI variations in different sites. The results of the index average for different sites location at each site showed that the water quality in the studied sites ranked as marginal or fair. This is attributed to the fact of the concentrations of heavy metals, ammonia and organic matter increase in sites that are more affected by drainage water from different drains in the study area. Great efforts are needed and wastewater must be treated before draining it into the River Nile water