Abstract: In view of the characteristics of ASTs on offshore oil storage platforms, and based on certain cases of offshore tank failure occurred in China over the years, this paper makes a deep analysis on the RBI-based assessment process of offshore ASTs, and expounds the necessity of such assessment in China. Risk is decided by failure probability and failure consequence, and parameters in close relation to failure probability include general failure frequency, damage factor and enterprise management coefficient. Offshore ASTs may suffer unique failure consequences that onshore ASTs don't have, with severity of such consequences being an order of magnitude higher than that of onshore ASTs. So, they are costly for equipment maintenance, shutdown loss, environmental cleanup and environmental penalties. The RBI-based assessment can be used for offshore ASTs, mainly aiming to optimize the testing cycle and define the testing strategy. This paper suggest the realization of accurate and quantitative RBI assessment by establishing offshore tank-specific RBI standards, developing the assessment software and building the risk assessment archive, so as to accumulate examples and data for application of offshore ASTs in projects.