We present theoretical investigations of the second and the thirdorder group d elay dispersion caused by a tilted birefringent filter (TBF). The expression for the group delay of TBF is deduced and the corresponding dispersions are calcula ted. The influence of the parameters such as the thickness, the tilting angle an d the rotation angle of the birefringent plate on dispersions are discussed. Com parison between the dispersion characteristics of a GiresTournois interferomet er (GTI) and those of TBF is also present.