Continuation of Quantum Mechanics I (introduction to quantum mechanics and quantum mechanics in one-dimension) including study of symmetries and perturbation theory. Applications to orbital angular momentum, spherical symmetric potentials (three-dimension square well potential, hydrogen like atom, three-dimension harmonic oscillator etc.), spin angular momentum, spin-orbit interaction and composition of angular momentum. A concept of symmetries is characterized by orbital angular momentum, spin angular momentum and interchange of the two particles.