Fundamentals of Quantum Mechanics can be used as a textbook for undergraduate courses in quantum mechanics for students major in physics or other related disciplines. This book contains eight chapters on matter waves, two-state systems, two-particle states and quantum entanglement, more problems of eigenvalues and eigenstates, electrons in atoms, electrons in solids, density matrices, and an introduction to quantum computation. Fundamentals of Quantum Mechanics strives to focus on the main content in the fastest and most effective way, with a special focus on the basic principles of quantum mechanics, the basic calculation rules requested by the principles, and their applications, accompanied by high-quality examples and exercises, and using "notes" to further expand the discussion of the key and difficult content. This will be especially helpful for beginners to achieve efficient and in-depth learning.