Cilutung watershed is one of the tributaries of Cimanuk river. The development of population activities in Cilutung watershed such as increasing settlements, industrial activities, and agricultural activities can cause physical, chemical, and biological changes in river waters. The research aimed to find out the level of the saprobic index in Cilutung watershed waters by using phytoplankton as bioindicator through saprobic index. The research conducted using survey method, where the determination of sampling station is performed with purposive sampling. Station placement is based on the estimated pollution load and surrounding community activities. The study was conducted at three different stations representing parts contaminated by the residents, sand mining industry, and agriculture. The study was conducted from February to May 2018. Environmental parameters were also measured in the study. The data in this study is quantitative data in the form and number of species of plankton, then calculated saprobic coefficient value with saprobic index method. The result obtained is related to table of water saprobic coefficient with water pollution level. Cilutung watershed has a range of saprobic values ranging from 0.75-0.86. The values obtained illustrate the waters are mildly contaminated in the β-Mesosaprobic phase, with less organic pollutants.