The nickelbased high temperature alloy GH4413 has excellent endurance strength and creep resistance at high temperature, and it is widely used in aviation engines and many industrial turbines. Liquid phase diffusion welding was applied on GH4413 alloy and BNi2 was used as filler material. The microstructure, composition distribution and microhardness of the welding joints were researched under different welding parameters when the welding temperature was 1 030 and 1 080 ℃, and heat preservation time was 30 and 60 min, respectively. The results of scanning electron microscopy (SEM) and energy spectrum analysis showed when the welding temperature was 1 080 ℃ and the heat preservation time was 60 min, the microstructure of brazing seam formed the solid solution with good performance. And as increasing the welding temperature and heat preservation time, the width of brazing seam increased and the diffusion depth of elements of solder to the base metal increased gradually, and intermetallic compounds were formed near the seam section of the parent metal.