Welcome to the 2025 International Symposium on Nonlinear Acoustics, which will take place in the beautiful city of Nanjing, China, from June 30th to July 4th, 2025. We are thrilled and deeply honored to host this prestigious event, gathering researchers, academics, and professionals from across the globe to foster scientific exchange, generate innovative ideas, and inspire groundbreaking projects in the field of nonlinear acoustics. The Institute of Acoustics at Nanjing University was founded by Prof. Rongjue Wei in 1954. It is the top acoustics department among Chinese universities, and has broad research directions, such as physical acoustics, nonlinear acoustics, biomedical ultrasound, photoacoustics, transducer engineering, electroacoustics and audio acoustics.