Abstract: The weld seam samples of the HFW pipe and that of the SAWL pipe made with the same material， OD and WT undergo flattening test，guided-bend test， tensile test， Charpy impact test， micro hardness test and metallographic test in a bid to comparatively analyze various properties of seam welds of the two different weld pipes. The analysis result leads to such a conclusion that produced with proper HFW process and post-welding heat treatment process，all the weld seam mechanical property data as tested of the HFW pipe are equivalent to those of the SAWL pipe，and even some properties are better. However，weld seam quality of the HFW pipe is less stable than that of the SAWL pipe，which means the manufacturing process needs to be further optimized，and the product quality from each operation step of the production line needs to be well controlled.