Classed ships are repaired according to the degree of damage after class survey. Then the ship conditions inclusive of damage are described in the survey report in detail. However it is difficult to judge objectively the soundness of the ship from the report as it is because of a great number of different conditions. So we arranged statistically the damage data of hull structures from survey reports, and we tried to evaluate the soundness of ships quantitatively by application of quantification theory and multicriteria analysis to the data. The main conclusions obtained are as follows ; (1) It is found that ships can be quantitatively classified into two groups depending on the level of soundness where the influential items such as age, ship kind and structural members are represented as quantities by application of quantification theory. (2) It is possible to evaluate the soundness of ship individually by means of concordance and discordance index which are obtained by the multicriteria analysis on the structural items, in which the weights given by quantification theory are also used. (3) A ship which indicates a negative value in the discordance index at a survey has a tendency to indicate increasing in its value at the next survey. Reversely, a ship with a positive value in the index at a survey has a tendency to indicate decreasing in it at the next one. In other words, this means that deterioration and effect of maintenance are well reflected in the index. As the result, it is concluded that the index can be an important measure on maintenance to judge ships condition individually.