Abstract: The composition of shale oil and neighboring shales with different lithofacies in well FY 1 in the Jiyang Depression of Bohai Bay Basin was analyzed with negative-ion electrospray ionization (ESI) and Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). The molecular compositions of pyrrole nitrogen compounds were compared. The heteroatom compounds of shale oil and two core extracts were mainly N₁ compounds. The high resolution mass spectrum and fingerprint details, the DBE and carbon number distribution of N₁ compounds, and the average molecular weight of N₁ compounds of three samples all showed that the composition of pyrrole nitrides in shale oil is similar to that of lamellar shale extracts, but different from the massive shale extracts. The ESI and FT-ICR MS has an ultra-high resolution and can effectively show the fine molecular composition differences of heteroatomic compounds in different types of samples. The analysis results can provide a reference for the near source tracing of terrestrial shale oil.