The study of dynamic equations on time scales, which goes back to its founder Stefan Hilger is an area of mathematics and has been created in order to unify the study of differential and difference equations. The oscillation theory as a part of the qualitative theory of dynamic equations on time scales has been developed rapidly in the past ten years. The extensive application prospect facilitates the development of this field. In fact there are some applications of dynamic equations in population dynamics, quantum mechanics, electrical engineering, neural networks, heat transfer, and combinatorics. The book tends to center around the relevant oscillation theory of second and third order dynamic equations and second order neutral dynamic equations on time scales. It is a text book giving detailed proofs and illustrative examples, which is intended for both self-study and a course for graduate levels. It is believed to be the first book dedicated to the oscillation of dynamic equations on time scales.