This book first introduced the theoretical foundation of nonlinear acoustics such as the basic equations of nonlinear acoustics followed by a statistical mechanics approach to nonlinear acoustics, then a curvilinear spacetime approach to nonlinear acoustics, then a gauge invariance approach to nonlinear acoustics, and application of chaos theory to nonlinear acoustics. Various formats of nonlinear acoustical imaging are given such as B/A nonlinear parameter acoustical imaging, fractal imaging, harmonics imaging, nonclassical nonlinear acoustical imaging, and modulation method in nonlinear acoustical imaging with their applications.