This book is written to impart knowledge on seismic refraction method, which covers data acquisition, processing and interpretation techniques. The discussion in this book is about seismic waves and their characteristics, theory of seismic refraction and field procedures. Examples of seismic refraction data and simple calculation are also provided to enable readers to better visualize and aid their understanding on the seismic refraction method. Rosli Saad is currently a lecturer at School of Physics, Universiti Sains Malaysia, Pulau Pinang with 30 years of experience in geophysics. His expertises is in the areas of Ground Penetrating Radar (GPR), gravity, magnetic, seismic and electrical methods. His main research is in engineering and environmental studies. He has published three research book chapters, four research books and more than 250 journal papers. Recently, he was appointed as head of geophysics section at the Centre of Tropical Geoengineering (GEOTROPIK), Universiti Teknologi Malaysia.