Abstract: A method for evaluating the maturity of passenger ship security controlling capacity is introduced. The security controlling capacity itself is looked into through direct investigation, questionnaire survey, and case record analysis, and a maturity index system composed of 16 indexes is set up. The weight of each index is calculated by means of Yaahp. The method to decide value of each index and the maturity level criteria are defined. The evaluation system is constructed based on the extension theory. With a Matlab program, the passenger ship President 6 is evaluated as an example. The calculation shows that, for the ship, the association degree matrix of the measured value of maturity to the level one indexes is(- 0.4095,0.2040,- 0.1355,- 0.5137,- 0.6641)^T, meaning the maturity is up to standard.