5A02 aluminium alloy was joined by transient liquid phase (TLP) bonding using the two-step heating process as follows: the faying area was first heated to 600uC and kept for 5 s and then cooled down to 595uC and kept for 3 min. The microstructure and properties of the joint were investigated and compared with that of conventional TLP bond at 595uC for 3 min. The results show that the two-step heating process can produce a wave bond line that is different from the planar interface associated with conventional TLP bonding at a constant temperature. The defects at the bond line are greatly reduced, and metal to metal contacts are established along the wave bond line using the two-step heating process. Therefore, the tensile strength and bending ductility of the joint are dramatically improved.