A method and an apparatus for encoding and decoding an orientation interpolator indicating the locations of keyframes on a temporal axis and the rotation of an object in each of the keyframes are provided. The apparatus for encoding an orientation interpolator includes an break point extractor which extracts, from a first animation path constituted by an orientation interpolator input thereinto, a minimum number of break points, which can bring about an error of no greater than a predetermined error limit between the first animation path and a second animation to be generated by the extracted break points, a key data encoder which encodes key data input from the break point extractor, and a key value data encoder which encodes key value data input from the break point extractor by generating rotational differential data, by which the object is rotationally transformed by as much as a difference between a rotational transformation value of a current keyframe and a rotational transformation value of a previous keyframe.