We report current status of active mirror support of Subaru telescope. Total wavefront error we provide for observation is 150-300 nm rms . Elevation dependency of the shape of the primary mirror and wind buffeting effect are shown. We also show a procedure for SH measurements at prime focus with half-cut (D-shape) pick-up mirror.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.