Abstract: Analyzed are the microstructures and mechanical properties of the L360N seamless steel linepipe with different heat treatment conditions, i.e., as-hot rolled, 1 hour-normalized at a temperature of 920 ℃, 3 hour-uniform annealed at a temperature of 1 150 ℃, and the combination of the latter two. The band areas and the non-band areas under the four different heat treatment conditions are compared. As a result, it is identified that the band structure of the L360N linepipe-purpose steel can be eliminated by means of long-time uniform annealing treatment at an elevated temperature, and that the band structure of the steel produces little influence on its tensile property, but strongly influences its impact property.