Every effort has been made to present the subject matter in easy, clear and systematic manner. The textbook has nine chapters. chapters in this textbook are general concepts of molecular genetics, the structure of DNA and RNA, genetic code and its translation, genes regulation and expression, polymerase chain reaction (PCR) technique, gene mapping and sequencing in animal production, blotting techniques, molecular genetics to identify the genes involved in cancer and application of molecular genetics in animal breeding. Each chapter has activities with brief answers. The author is a Assistant Professor in Animal Genetics and Breeding in Woldia University College of Agriculture in department of animal science. The author is animal geneticist and breeder.