The invention discloses a method for determining a profile of a two-dimensional Lab color gamut map and a device thereof, which relates to the method for determining the profile of the two-dimensional Lab color gamut map which can rapidly determine the outermost profile of distribution region of a plurality of sampling points in two-dimensional space. The method for determining the profile of thetwo-dimensional Lab color gamut map comprises the following steps: sampling points are determined in the two-dimensional color space; all sampling points which are positioned at the outermost side ofthe distribution region of the sampling points are determined; and all sampling points which are positioned at the outermost side of the distribution region of the sampling points are sequentially connected to form the closed profile of the two-dimensional Lab color gamut map. The device comprises a sampling point determining unit used for determining the sampling points in the two-dimensional color space, an outermost sampling point determining unit used for determining all sampling points which are positioned at the outermost side of the distribution region of the sampling points and a profile forming unit used for sequentially connecting all sampling points which are positioned at the outermost side of the distribution region of the sampling points and forming the closed profile of thetwo-dimensional Lab color gamut map. The invention is applicable to computer graphic processing.