A simplified configuration of variable stator vanes, which has a uniform hub clearance and a stationary hub surface, is applied to a high-loaded multistage compressor. Comparisons of endwall flow structures are made between the ideal and the simplified configurations. After validating numerical results of the ideal stator configuration with experiment data, the third stator and all stators are modified with the simplified configuration in two separate cases. Flow structures and loss characteristics in the endwall region are investigated numerically in detail at design point. Limited corner separation near the suction side and comparatively strong secondary flow near the pressure side make similar contributions to endwall loss at design point for the baseline configuration, while the shear flow of the blade tip and the endwall boundary layer are regarded as important sources of loss for the modified configuration.