Abstract: The most commonly used method to estimate the service life of a tubular joint in offshore engineering is by referring to S-N curves. The hot spot stress (HSS) range along the weld toe is obtained by either numerical method or experimental test if a tubular joint is subjected to fatigue loadings. From a corresponding S-N curve, the number of fatigue loading cycles that the joint can sustain before failure can be predicted according to the HSS range. The HSS range is frequently calculated from a parameter called stress concentration factor (SCF). In this study, numerical and experimental analyses of the SCFs of tubular K-joints subjected to basic loadings were conducted. The stress distributions along the weld toe and the corresponding locations of the peak SCF values of the K-joints subjected to different basic loadings were obtained.