Abstract: Based on the characters of durability failure of marine structures and requirements on structural durability in seasonal ice, a reliability model of prestressed structures with chloride attack and cyclic freeze-thaw was put forward from the relationship of failure rate and reliability as well as random field theory, according to the influence of positive and negative peak temperature difference, chloride concentration and prestressing force. The influence of discrete variable number to failure probability was discussed and the sensitivity of correlation random variables was analyzed, such as chloride concentration, cover and so on. It is showed that the results are agreed well with the numerical results of the JC method and the practical analytical method. The results reported herein could provide reasonable preparations for the reliability analysis in engineering application.