Ordinary Differential Equations (ODE) is an extension to the topic of differentiation and integration learned at the secondary school level. This book was released to help students understand more easily how to solve ordinary differential equations (Ordinary Differential Equations), especially for engineering students. A simple and more detailed solution is expected to help students in self-learning. An online Quiz link is also provided to test students' understanding. Hopefully with the availability of this book can add to the collection of reference books that are already in the market.