This volume is a collection of the Nobel lectures delivered by the prizewinners in physics, together with their biographies, portraits and the presentation speeches for the period 1996-2000. Each Nobel Lecture is based on the work that won the prize. This volume should be useful to physicists, students, teachers and professors of physics as well as those in related fields. Below is a list of the prizewinners during the period 1996-2000 with a description of the works for which they won the prizes: D.M. Lee, D.D. Osheroff and R.C. Richardson (1996) - for their discovery of superfluidity in helium-3; S. Chu, C. Cohen-Tannoudji and W.D. Phillips (1997) - for development of methods to cool and trap atoms with laser light; R.B. Laughlin, H.L. Stormer and D.C. Tsui (1998) - for their discovery of a new form of quantum fluid with fractionally charged excitations; G't Hooft and M.J.G. Veltman (1999) - for elucidating the quantum structure of electroweak interactions in physics; Z.I. Alferov and H. Kroemer (2000) - for developing semiconductor heterostructures used in high-speed and opto-electronics; and J.S. Kilby (2000) - for his part in the invention of the integrated circuit.