We discuss some of major developments of last two decades in the field of rheology, with a particular emphasis on viscometric flows. This lecture consists of five parts : （1） Newtonian fluids, (2) kinematics/dynamics, (3) constitutive equations, (4) viscometric flows of a simple fluid, and (5) viscometers. A book under the same subtitle by Coleman, Markovitz and Noll is used as the text.