Purpose. Identifying of anomalous magnetic field peculiarities upon oil-and-gas bearing structures in the Carpathian Feoredeep and its relationships with oil and gas deposits. Methodology. Measuring of geomagnetic field T total vector modulus during surface magnetic survey on a geomagnetic profiles network. Measuring of core magnetic susceptibility of searching-prospecting wells. Investigations were done for 9 hydrocarbon deposits and 6 perspective structures in the NW part of Bilche-Volytsa zone, Carpathian Foredeep. Results. The analysis of anomalous magnetic field is shown.