In the previous paper, the authors showed that the transient response method was effective for research on longitudinal ship motions in waves. According to this method, three kinds of experiments (i. e. Transient forced pure pitch test, Wave exciting forces test in transient water wave and Ship model motion experiment in transient water wave) were carried out. Then the comparison of the experimental results with the calculated values by O. S. M. was made in detail with respect to the coefficients of the equation of motion, the wave exciting forces and the ship motion (pure pitch). The authors could certify that the testing ship models by the transient response method was applicable to Pure Pitch when the phenomena were linear.