Chemical biology primarily focuses on the examination and manipulation of biological systems by using natural or synthetic chemical entities. Chemicals including natural small molecules like metals, lipids and carbohydrates, as well as non-natural probes or medication molecules are used to acquire mechanistic insights into biological issues. It aims to improve understanding of the manipulation of ecological and environmental biosystems. It is also applied in human biology and medicine, plant biology, and veterinary science. The compounds and substances found in nature are known as natural products. They have a structural diversity and distinctive biological or pharmacological activities as a result of natural selection and evolutionary processes. Research on natural products in chemical biology involves the study of chemical properties, biosynthesis and biological functions of secondary metabolites. This book aims to shed light on the use of natural products in chemical biology. It will also provide interesting topics for research, which interested readers can take up. Through this book, we attempt to further enlighten the readers about the new concepts in this area of study.