A simple technique for the flow property analysis of a power law fluid with the terminal velocity of a falling body in a Viscous fluid has been developed for process control of a chemical plant. A falling needle viscometer was used as the experimental equipment, and a slender hollow cylindrical needle of which both ends are hemispherical was applied to falling body. As the fluid model of laminar flow, the fluid behavior between the falling needle surface and container wall was analyzed, and Stokes type equation was introduced for the calculation. Shear stress and shear rate at the surface of each needle were calculated with the terminal velocity of the falling needle and the density difference between the sample fluid and needle. Analysis of the flow property in power law fluid was carried out in accordance with the following procedure. (1) Measurement of density difference between fluid and needle. (2) Measurement of terminal velocity of falling needle in fluid. (3) Calculation of shear stress and shear rate at needle surface. (4) Determination of parameters in constituted equation. (5) Drawing of constituted flow curve. As for this analysis, U-t- (rho(s)- rho(f)) and log U-t-log(rho(s)- rho(f)) diagrams which were described by use of the experimental data, are very similar to that of tau-gamma and log tau-log gamma diagrams, respectively. It is found that the flow curve configuration for a power law fluid can be predicted from the data of terminal velocity and density difference. As a result of experiments of some model fluids, it is verified that the method using a viscometer presented here could be effectively applied to high viscosity fluid and that the application is available for such Power law fluid as polymer solution and suspensions containing fine particles. Further, an analytical method by use of a computer system is also presented for the fluids.