This paper features the development of angle-dependent linear source (ADLS) approximation for the 2D/3D Method of Characteristics (MOC)/Diamond Differencing (DD) method and its performance analysis simulation. The ADLS MOC/DD applies the linear source approximation to two different types of sources, the sum of fission and scattering source and the angle-wise surface source appearing in the MOC/DD equation. It is demonstrated memory usage and simulation time can be reduced by increasing the source approximation order from the zeroth to the first order.