At the calculation of the frequencies of the flexure vibration of wooden ships, if we use the formulae developed from the structural theory of steel ships, we obtain very high values as compared with the real frequencies. For example, the measured frequency of a 57 Ton-type fishing boat is 275 per minutes, and on the other hand the calculated value of this ship is 628 per minutes. From where is this difference derived? For the first step to solve this problem, theoretical and experimental studies are developed in this paper.