In this study, the aim was to find out the base sector of Sampang Regency on Madura Island, through the GRDP data of Sampang Regency. The analysis used uses several analyzes, namely analysis of Location Quotion (LQ), Dynamic Local Quotion (DLQ), Shift-Share (SS), Growth Ratio Model (MRP). Based on the analysis conducted, it can be seen that several sectors in Sampang Regency have good potential, such as the Agriculture, Forestry and Fisheries sector, Mining and Excavation, and the Compulsory Government, Defense & Social Security sectors. By knowing the sectors that have potential and those that are still lagging behind in Sampang Regency, it can become a material for the Sampang Regency Government to make policies toincrease the value of GDP and economic growth in Sampang Regency.