Optical Coherence Tomography (OCT) has been developed for more than one decade. With the optimum of system
configuration such as light source, the imaging elements, the imaging quality has been improved to a higher level.
However, many ideal assumptions including dispersion cancellation. in the study of OCT system have become
inapplicable. Actually, dispersion, can lead to a wavelength dependent phase distortion in sample arm, and finally result
in a degrading in image resolution. Therefore, many dispersion compensation methods have been presented by
researchers to correct the distorted image. In this paper, the principle of dispersion in OCT imaging system is discussed,
and we demonstrate how it affects image quality. Then, with respect to the compensation methods as our knowledge, we
classify them into hardware compensation and software compensation and present the detailed procedures and their
characteristics, respectively. At last, a detailed discussion has been made to conclude that novel algorithms which can
perform higher order compensation with depth variant are necessary and uniform evaluating criteria as well.