Abstract: Due to the huge reserves all over the world, heavy crude oil has wide application prospects. However, because of its high density and high viscosity, the traditional production technologies are severely challenged. The asphaltene dispersant is one of the vital approaches to solve the aggregation of asphaltene and improve the flow ability of heavy crude oils. In this work, comb-type poly(maleic anhydride-co-α-olefin) (MAC) derivatives with phenyl, naphthyl and benzimidazole pendants (AMAC, NMAC and MACB) were synthesized. The effect of comb-polymers on the onset of asphaltene deposition, size distribution and aggregation behavior of asphaltenes in model oil were studied by means of UV-vis, turbidity meter, dynamic light scattering (DLS) and optical microscopy. The results show that the sequence of dispersion effect is:NMAC > AMAC > MACB, when their grafting ratio is similar and the dosage is 50 mg/L. For NMAC, the "onset of asphaltene deposition" is postponed by about 20%. The average size of aggregates was reduced by half and the size distribution was narrowed. The aggregation morphology of asphaltene was changed from the large-sized flocculated aggregates to the small-sized dispersed aggregates as observed by optical microscope. It indicates that the π-π conjugation interactions between aromatic pendant and asphaltene play an important role, but the hydrogen bonding between them is relatively weak which is resulted from the few heteroatoms in the periphery of aromatic rings of asphaltene. Under the effect of these copolymers, asphaltene can be well dispersed in the oil, which indicating that they are good candidate additives for the recovery and transportation of heavy oil. Meanwhile, by knowing the interactions between the different aromatic pendants and asphaltene, the structure-performance relationship could be built. It indicates a practical direction for developing more efficient macromolecular asphaltene dispersants.