  We present results of an analysis of the optical spectrum of the post-AGB
star HD56126 (IRAS 07134+1005) based on observations made with the echelle
spectrographs of the 6-m telescope with spectral resolutions of R=25000 and
60000 at 4012-8790 AA. The profiles of strongest lines (HI; FeII, YII, BaII
absorptions, etc.) formed in the expanding atmosphere at the base of the
stellar wind have complex and variable shapes. To study the kinematics of the
atmosphere, the velocities of individual features in these profiles must be
measured. Differential line shifts of up to Vr=15-30 km/s have been detected
from the lines of metals and molecular features. The star's atmosphere
simultaneously contains both expanding layers and layers falling onto the star.
A comparison of the data for different times demonstrates that both the radial
velocity and the velocity pattern in whole are variable. The position of the
molecular spectrum is stable, implying stability of the expansion velocity of
the circumstellar envelope around HD56126 detected in observations in the C_2
and NaI lines.
