Kim, S., Chung, W.K. and Lee, J.H., 2021. Acoustic full waveform inversion using Discrete Cosine Transform (DCT). Journal of Seismic Exploration, 30: 365-380. Full waveform inversion (FWI) has been implemented widely to reconstruct high-quality velocity model in the subsurface. However, due to the advance in geophysics data acquisition with increasing demand for high dimension velocity model estimation, computational costs become prohibitive if not impossible. To alleviate computational burdens, we incorporate discrete cosine transform, one of the most widely used compression techniques in image processing, into FWI while estimation results are still kept comparable to those from the full-model based FWI. The unknown velocity fields are transformed in the DCT domain and only a small number of DCT coefficients are included in FWI to describe common velocity model features without losing much reconstruction accuracy. Generally, DCT coefficients can be chosen specific window (e.g., square window). However, there can be more dominant DCT coefficients out of this specific window. To take more dominant DCT coefficients, we sort the absolute value of DCT coefficients in descending order and determine DCT coefficients with compression ratio. Through the comparison reconstructed velocity models, our proposed method generate more accurate velocity model than case of using square window. We investigate the applicability of our DCT-based FWI method to two numerical examples. It is shown that the proposed method can reduce the computational cost significantly and produce satisfactory results. Through these results, we expect that our FWI method can contribute to enhance computational efficiency for FWI with enormous amount of unknown parameters.