Abstract: The growth of columnar grain during the solidification of the 1Cr18Ni9Ti stainless steel weld metal for different welding parameters is simulated using the grain boundary evolution (GBE) modeling method.The shape and the size of the weld pool under different welding parameters are calculated using PHOENICS software. The simulated results show that the growing direction of the columnar grains is dependent on the shape of the weld pool.The straight and short grains tend to grow in direction perpendicular to the weld centerline if the length/width (L/W) of the weld pool is large and the curving and long grains grow toward the welding direction if the L/W ratio is small.The experimental results are found to be in good qualitative agreement with the simulated results.