Measurements of pressure at representative points in a converging–diverging channel were carried out for viscoelastic liquids of aqueous solutions of poly‐ethyleneoxide (PEO) and polyacrylamide (PAA) as well as for Newtonian liquids. The pressure drop at the section of converging channel and the pressure rise at the section of diverging channel were simultaneously measured for various flow rates. The experimental results indicate that (i) magnitudes of both pressure drop and rise for the PEO solution increase with increasing PEO concentration, and the pressure characteristics are similar to those of Newtonian liquids, (ii) the pressure characteristics of the PAA solution are significantly different from those of Newtonian liquids when the PAA concentration is increased. The differences seem to be due to elasticity of the PAA solution.