R is now widely acknowledged as a scientific skill and increasingly more applied in many scientific area because of its powerful and flexible and also can be freely downloaded and installed in many platforms (Windows, MacOSX and Linux). This open source licence along with a relatively simple scripting syntax has promoted diverse and rapid evolution and contribution, make the popularity of R as a teaching and research tool continues to accelerate. This book discusses theory and application of experimental design, especially in animal and agricultural science, and shows how R can be friendly used as a tool in data analysis although the use of excel or hand calculation is not ruled out. I believe that this book is useful to student and researcher in learning process, to help them in applying appropriate experimental designs and statistical methods using software R.