To investigate the low temperature fatigue crack propagation behavior of offshore structuralsteel A131 under random ice loading,three ice failure modes that are commonly present in the Bohai Gulfare simulated according to the vibration stress responses induced by real ice loading.The test data are pro-cessed by a universal software FCPUSL developed on the basis of the theory of fatigue crack propagationand statistics.The fundamental parameter controlling the fatigue crack propagation induced by randomice loading is determined to be the amplitude root mean square stress intensity factor K_(arm).The test resultsare presented on the crack propagation diagram where the crack growth rate da/dN is described as thefunction of K_(arm).It is evident that the ice failure modes have great influence on the fatigue crack propaga-tion behavior of the steel in ice-induced vibration.However,some of the experimental phenomena and testresults are hard to be physically explained at present.The work in this paper is an init To investigate the low temperature fatigue crack propagation behavior of offshore structural steel A131 under random ice loading, three ice failure modes that are commonly present in the Bohai Gulfare simulated according to the vibration stress responses induced by real ice loading. The test data are pro-cessed by a universal software FCPUSL developed on the basis of the theory of fatigue crack propagation and statistics. The fundamental parameter controlling the fatigue crack propagation induced by randomice loading is determined to be the amplitude root mean square stress intensity factor K_ (arm). The test resultsare presented on the crack propagation diagram where the crack growth rate da / dN is described as the function of K_ (arm). It is evident that the ice failure modes have great influence on the fatigue crack propagation behavior- the steel in ice-induced vibration.However, some of the experimental phenomena and testresults are hard to be physically explained at present. work in th is paper is an init