In this paper the early activities and influence of L. M. Brekhovskikh in the development of underwater acoustics in China are reviewed. The activity of Brekhovskikh as an invited underwater acoustics expert in the formulation of the 12-year plan of S&T development of China in 1956 is described. This paper reviews the early development of underwater acoustics in China, including the visit of Chinese experts to the Institute of Acoustics in Russia, the first joint Sino–Russian experiment in the South China Sea, and the training of young Chinese scientists. The monograph ‘‘Waves in Layered Media’’ has had a large influence on Chinese underwater acoustics. This paper also reviews part of the research on underwater acoustics in China. The ray-mode theory was developed, improved, and used in propagation, reverberation, and noise field modeling in shallow water. The relationship between rays and normal modes was analyzed and proved. The influence of sea bottom in shallow water was expressed in terms of angular dependence of bottom reflection loss. Wave theory for long-range reverberation was developed. MFP, MMP, and other methods of positioning and inversion was developed. Internal waves and their influence on sound propagation were studied.