A production method of an optical fiber preform includes: preparing a plurality of bar-shaped first preforms and a plurality of second preforms including through holes having substantially same shape with a shape of outer periphery of a cross section of the first preform, the cross section being orthogonal to a major axis of the first preform; and an assembly step of: matching the through holes of the second preforms to make communication holes; and inserting, through each of the communication holes, at least two of the first preforms arranged side by side in a direction of the major axis such that the second preforms and the first preforms are fitting each other. In at least one position in the direction of the major axis of the communication holes, a position where the second preforms contact with each other differs from a position where the first preforms contact with each other.