Abstract: The content, distribution and forms of the ferrum or calcium compounds in a crude oil, the corresponding vacuum residue (VR), hydrogenation feedstock and hydrogenation products were studied. The separation method was studied by column chromatography and solvent extraction method. This work indicated that in the process of column chromatographic separation, some ferrum or calcium compounds in the oil samples were irreversibly adsorbed on the chromatographic column, resulting in the loss of 58% of the ferrum compounds and 76% of calcium compounds. The solvent extraction method could effectively reduce the loss of the metal components and was suitable for the study of the content of metal elements. More than 97% of the ferrum or calcium compounds were distributed in the VR fraction. The 60% to 90% of the ferrum or calcium compounds were distributed in the resin and asphaltene components. During the hydrogenation reaction, the ferrum or calcium compounds in vacuum residue were mainly removed from the resin components, and the overall removal ratio was close to 30%. The ferrum compounds prefered to bond in the asphaltene components and were difficult to remove. Through the process of atmospheric distillation and vacuum distillation of the crude oil, the relative distribution of the oil-soluble ferrum compounds decreased from 95.6% to 64.7%, and the relative distribution of the water-soluble ferrum compounds increased from 4.4% to 35.3%. Through the process of the hydrogenation reaction, 38% of the oil-soluble ferrum compounds were converted into the water-soluble ferrum compounds and 30% of the oil-soluble calcium compounds were converted into the water-soluble calcium compounds in the reaction.