Two attapulgite powder (AP)-supported nickel catalysts were prepared by thermally decomposing nickel tetracarbonyl onto AP in a laboratory (L-Ni/AP) and in a factory (F-Ni/AP). The Ni nanoparticles are successfully dispersed on AP without evident agglomeration and mainly exist on the surface of AP in crystalline form with a small part entering into the mesopores. The soluble portion from non-catalytic hydroconversion (SPNCHC) and catalytic hydroconversion (SPCHC) of a high-temperature coal tar (HTCT) in cyclohexane over L-Ni/AP (SPCHC-L) and F-Ni/AP (SPCHC-F) were analyzed with a gas chromatograph/mass spectrometer and a quadrupole exactive orbitrap mass spectrometer with an APCI source operating in positiveion model. The results show that the distribution of group components detected in SPNCHC are obviously different from that in either SPCHC-L, or SPCHC-F. The relative content of non-substituted condensed arenes in SPCHC is ca. 75.0%, while the non-substituted polycyclanes and non-substituted hydroarenes are dominant in SPCHC-L and SPCHC-F The relative abundances (RAs) of N3Ox (x = 0-2) class species are predominant in SPNCHC, while the RAs of hydrocarbons, N1Ox and O-x (x = 1,2) class species in SPCHC-L, and SPCHC-F are the most abundant. Both catalysts are active for removing heteroatoms from the HTCT and hydrogenating aromatics in the HTCT, while L-Ni/AP is more effective for catalyzing the hydrogenation of the aromatics.