The <TEX>$BaHfO_3$</TEX> (BHO) buffer layer on the IBAD MgO template was turned to be effective for a successful fabrication of <TEX>$GdBa_2Cu_3O_{7-{\delta}}$</TEX> (GdBCO) films with high critical current density (<TEX>$J_c$</TEX>). Both the BHO buffer layers and GdBCO films were prepared by pulsed laser deposition (PLD). The effects of the PLD conditions, including substrate temperature (<TEX>$T_s$</TEX>), oxygen partial pressure (<TEX>$PO_2$</TEX>), and deposition time on the in-plane texture, surface roughness, and microstructures of the BHO buffer layers on the IBAD MgO template were systematically studied for processing optimization. The c-axis oriented growth of BHO layers was insensitive to the deposition temperature and the film thickness, while the in-plane texture and surface roughness of those were improved with increasing <TEX>$T_s$</TEX> from 700 to <TEX>$800^{\circ}C$</TEX>. On the optimally processed BHO buffer layer, the highest <TEX>$J_c$</TEX> value (77 K, self-field) of 3.68 <TEX>$MA/cm^2$</TEX> could be obtained from GdBCO film deposited at <TEX>$780^{\circ}C$</TEX>, representing that BHO is a strong candidate for the buffer layer on the IBAD MgO template.