This book is the second part of the text Differential Equations: A Dynamical Systems Approach written by John Hubbard and Beverly West. It is a continuation of the subject matter discussed in the first book, with an emphasis on systems of ordinary differential equations. This book will be most appropriate for upper level undergraduate and graduate students in the fields of mathematics, engineering, applied mathematics, as well as in the life sciences, physics, and economics. This book opens with an introduction, and follows with chapters on systems of differential equations, systems of linear differential equations, and systems of nonlinear differential equations. The book continues with structural stability, bifurcations, and an appendix on linear algebra. The authors also include an appendix containing important theorems from parts I and II, as well as answers to selected problems.