A method for reducing metal artifacts in computed tomography (CT) is disclosed. The method for reducing metal artifacts in CT includes: obtaining a sinogram reduced in size from an original sinogram; setting up a linear algebraic equation according to remaining data excluding data damaged by a metal based on the obtained sinogram; restoring a low-resolution image based on the set up linear algebraic equation; calculating a sinogram from the restored low-resolution image; restoring a sinogram by disposing the calculated sinogram data in the original sinogram and by utilizing the calculated sinogram data as pre-information; and restoring a final CT image from the restored sinogram. Through introduction of a novel metal artifact reduction (MAR) technique referred to as an algebraic correction technique (ACT) using an intermediate image of an attenuation coefficient of an outside of a metal area, an image closest to an original image can be obtained by minimizing metal artifacts in CT.