A seek control method of smoothly changing to a coast mode and a deceleration mode in a track-seek control device according to a multi-sinusoidal acceleration trajectory, a recording medium suitable for the same, and an HDD adopting the same. The method includes: calculating time of an accelerating duration from a position trajectory corresponding to a maximum seek distance that can be reached without the coast mode; calculating a position trajectory for a seek control including a coasting duration based on the time of the accelerating duration; calculating an acceleration trajectory and a velocity trajectory corresponding to the calculated position trajectory; and performing the seek control including the coast mode using the calculated acceleration trajectory, velocity trajectory, and position trajectory. Accordingly, in the seek control of the HDD including the coast mode, the coast mode can be smoothly controlled by obtaining the time of an acceleration duration from a position trajectory for track-seeking without the coast mode and calculating an acceleration trajectory, a velocity trajectory, and a position trajectory for a seek including the coast mode based on the obtained time of the acceleration duration.