The solubility of hydrogen in Venezuelan heavy coking gas oil (HCGO), Karamay atmospheric residue (KRAR), Liaohe atmospheric residue (LHAR), and Venezuelan atmospheric residue (VNAR) was measured at temperatures in the range 150 degrees C to 350 degrees C at pressures up to 11 MPa by a modified direct method. The measurement accuracy and reliability were examined by determining hydrogen solubility in toluene and n-heptane at temperatures of 25 degrees C, 50 degrees C and 100 degrees C, and results are in a good agreement with the data reported. The order of hydrogen solubility in the four feedstocks at the same experimental condition is VNAR < LHAR < KRAR < HCGO. The impact of oil properties, such as aromatic ring number and alkyl chain length, on hydrogen solubility was discussed. The results indicate that the condensed aromatics play a key role in the fractions of high boiling points. The hydrogen dissolving capacity in different derived oils with the same boiling range can be tentatively determined via analyzing the H/C atomic ratio of the oils.