A t the time, the production of hydrocarbons in Water Cut in the fieldwill increase. In other words, when water levels are high, then reduce the levels ofhydrocarbons produced. In addition to water study also cut using the equation ofFractional Flow as one of the methods of calculation are used. Fractional Flowequations used to qualitatively shows the ratio of the flow rate of the water againstthe flow rate of the fluid at a certain period and space in the linear water injectionsystem. This equation shows the relationship between the amount of water flow oneach area of the reservoir with the amount of water saturation.Therefore the authorintends to conduct a study of the calculation of the cutoff on Sw FYTO Field basedon the data of the well x located in Kalimantan.The data includes Core data x wellsand production data.The last stage of using statistical data by performing the depiction onthe parameters of the Sw vs. Fw and Sw vs WC\'s “Study Effect Flow Unit ForDetermination Sw Cutoff With Fractional Flow Equation And Water Cut At FytoField”. In determining the value of a Sw cutoff for achieving the objectives of thisresearch are required parameters in the form of data-data available i.e. Core data,data PVT, data as well as data production . processed in order to obtain the desiredresults. After performing the stages that have been mentioned above, the results areobtained in the form of Fractional Flow and Water Cut then will be in the plot in agraph of against water saturation.water