The wetting of AlN by molten Cu-8.6Zr-xTi (x=0, 5, 7.5, and 10 at.%) ternary alloys was conducted by the modified sessile drop method at 1373 K under a high vacuum. AlN cannot be wetted by Cu-8.6Zr binary eutectic alloy even though the precipitation of zirconium nitride at interface, while the addition of Ti in Cu-Zr eutectic alloy upgraded the wettability significantly. Based on the thermodynamic analysis, the interfacial reaction sequence leads to the preferential precipitation of zirconium nitride, and thus a bilayer reaction layer (zirconium nitride bottom and titanium nitride upper) was formed at the interface in Cu-8.6Zr-xTi/AlN. The final wettability was determined by the wetting nature of the reaction product (titanium nitride and stoichiometry in it) and the adsorption of Ti addition at interface. The spreading dynamics were further influenced by the interfacial reaction sequence, and presented two stages, first corresponds to the precipitation of zirconium nitride, and then corresponds to the precipitation of titanium nitride. © 2020