Geotechnical engineering is one of the major branches of civil engineering.Generally, geotechnical engineering discusses with the physical properties of soils and requirements of a good and weak soil. Soil is the material that is very unpredictable. Soil quality vary widely in the different location. Soil properties also vary a lot. In the field of geotechnical engineering, fundamentals of geotechnical engineering by B.M. Das is one of the most anticipated book. this book contains almost everything that is basic of geotechnical engineering. Many emphirical relationships are newly added in this edition. Many equations also presented in seepage,hydraulic conductivity and soil compaction topics. The book is re-organised in the fourth edition.