Biological invasion is a process wherein certain organisms are introduced into a new ecosystem, where they did not exist previously. It may be a natural process or may be done deliberately. These organisms are called invasive species. They may have an adverse or positive impact on the native inhabitants and natural resources of the ecosystem they invade. Some common characteristic features of invasive species include rapid reproduction and growth, phenotype plasticity, high dispersal ability, ability to tolerate a broad spectrum of environmental conditions, and prior successful invasions. They also have an ability to survive by consuming various types of foods. Some invasive species have favorable effects, such as, providing a suitable habitat or food for the native species. Invasive species can play a crucial role in restoring the native place, where the indigenous species have reached a point of extinction. The topics included in this book on biological invasions in changing ecosystems are of utmost significance and bound to provide incredible insights to readers. It is appropriate for students seeking detailed information in this area of study as well as for experts.