A method of reducing memory effect of a power amplifier (PA), for a look-up table (LUT) based memory digital pre-distortion (DPD) circuit of an electronic device is disclosed. The method comprises generating a pre-distorted signal according to a LUT including parameters of an input signal amplitude and an input signal delay associated with a bandwidth of a signal inputted to the memory DPD circuit, and outputting the pre-distorted signal to the PA for improving the nonlinearity of the PA.