Abstract: Compared to the conventional line commutated converter based high voltage direct current(LCC-HVDC) system, Yongfu HVDC project can operate at full power transmission mode and power distribution transmission mode for the inverter station. However, the interactive oscillation modes of LCC-HVDC system in the split-connection mode and their characteristics are unclear. Aiming at this special operation mode, this paper adopted the modular modeling method to establish the system motion equation model which the interactive coupling paths among different electrical and control loops. On this basis, according to the interactive coupling paths between the rectifier and inverter sides or between the positive and negative poles, three disturbance transfer paths which influence the stability of the system dominant mode were separated, i.e., the self-stabilizing path of the rectifier side, the self-stabilizing path of the inverter side and the en-stabilizing path of bipolar interaction. Finally, the cases under different working conditions were set to quantitatively evaluate the damping provided by different transfer paths. Also, the motion equation model and the analysis results based on the disturbance transfer paths were verified by simulation, which provided the model basis for the subsequent investigation on the damping characteristics of the interactive oscillation modes of the LCC-HVDC system in the split-connection mode.