Parametric Polynomial Method is used to analyze the three dimensional viscous flow through multistage turbomachines. Three high pressure stages in a 20MW steam turbine are calculated at design flow rate and small llow rate (G/G0 = 0.3). Large separated flow is predicted in the passage at small flow rate. The result shows that the upstream flow has a conspicuous effect on the downstream flow, so the multbetage fiow calculating is
