Abstract: In order to study the monotonic tensile fracture performance of Q690 high strength steel butt welded joint, the hardness test was carried out in each area of the welded joint, and the hardness distributions of base metal, weld metal and heat- affected zone were determined. Then monotonic tensile tests were carried out on samples of welded joints of high strength steel to study the fracture properties of base metal, weld metal, softened and hardened zones of heat-affected zone under monotonic tensile conditions. According to the test results, the parameters of VGM and SMCS ductile fracture models in each region were calibrated, and the fracture performance of each region was obtained. Comparing the fracture performance of different regions, it is found that the fracture performance index of the hardened zone is greatly improved compared with the base metal, while the softened zone is greatly decreased compared with the base metal. The numerical simulation of base metal, weld metal, hardened zone and softened zone with calibrated VGM and SMCS ductile fracture models can well predict the fracture performance of Q690 high strength steel butt welded joints under monotonic tension.