The fusion dynamics of 16O + 154Sm and 18O+148Nd reactions has been investigated to observe the effect of shape degree of freedom on the fusion cross-section using the coupled channel (CC) calculations. The one dimentional barrier penetration model (1-D BPM) is observed to underestimate the experimental data mainly at below barrier energies. The coupled channel calculations, including target projectile excitations with 1 phonon of vibrational state and 2+ rotational state of target, reproduce the experimental fusion cross-section for 16O + 154Sm reaction at below barrier energies, while show some discrepancy for 18O+148Nd reaction. This discrepancy for 18O+148Nd reaction can be addressed with the inclusion of low-lying states with neutron transfer channels and the neck-formation.