This paper shows the results obtained on actual ships by using the method presented before in “A New Procedure of Manoeuvring Model Experiment”. The purpose of this paper is to determine these four characteristic constants K ', T ₁', T ₂' and T ₃' of actual ships by means of frequency response analysis of a parallel shift manoeuvring and trapezoidal steering tests with fixed periods. This procedure gives enough informations of frequency response characteristics of a ship at practically important frequencies. As an additional attempt this paper deals with a ψ-ψ phase plane analysis on a parallel shift manoeuvre to determine the characteristic constants K ', T ₁', T ₂' and T ₃'. Full-size experiments were carried out for eight actual ships, ranging from a 360 GT training ship to a 220, 000 DWT oil tanker. The conclusions obtained are that : 1) the combination of the parallel shift manoeuvre and periodic trapezoidal steering is a promising procedure for full-size steering test to determine the steering characteristic constants K ', T ₁', T ₂' and T ₃'. 2) both steering tests mentioned above are also applicable to the phase plane analysis, and this analysis can be used to determine the reasonable characteristic constants together with the frequency response analysis. 3) the steering transfer function, Y_s ( iω ), obtained from the frequency response analysis in the intermediate frequency range provides useful data in connection with K ' T ₃'/ T ₁' T ₂' to determine whether the course keeping ability, especially in the case of the automatic steering, is sufficient.