A filter method and an apparatus of a low complexity Finite Impulse Response (FIR) filter, and a recording medium thereof are provided. A filtering method of the low complexity FIR filter includes filtering input signals using 2N-ary filters by dividing 2N-ary filter coefficients into even filter coefficients and odd filter coefficients; filtering using a (2N+1)-th filter and the input signals; and adding up a filtering result of the 2N-ary filters and a filtering result of the (2N+1)-th filter. Hence, by reducing the computations of the FIR filter, the FIR filter with the optimal performance can be realized.