iarjimphIARJIMPHIARJIMPH2709-331Xhttps://doi.org/10.47310/iarjimph.2021.v02i02.014Oil Waste of Ships Lab Tests and Its Effects on Planktonic Diversity of Port of Belawan, IndonesiaEdiAzwarSaifulAnwarMatondangSyahlanOil waste has been noted to be pollutant in the Belawan Fisheries Port of Indonesia.  This research was conducted in the administrative area of the Nusantara Belawan Fisheries Port as a place to dock and get out or enter fishing boats from and to the sea. Seeking the effect of oil waste and other physical-chemical parameters of water on the diversity of plankton in the waters of the Nusantara Belawan Fisheries Port in two ways: First, the data were analyzed partially using simple regression analysis. Second, data are analyzed simultaneously by using multiple regression analysis stages. Data obtained showed that the water brightness gives a positive effect on planktonic diversity at the Fishing Port reached 84.70%. Dissolved oxygen gives a positive effect on planktonic diversity at the Fishing Port 91, 56%. Oil waste level on the water gives a negative effect on the planktonic diversity at the Fishing Port reached 94.61%. The result of simultaneously data analysis of parameters such as water brightness, dissolved oxygen, and oil waste level on the water give a negative effect on planktonic diversity at the Fishing Port about 97.89%.