Samples of 2 com. high-d. polyethylenes were studied for dynamic viscosity and elasticity at 150-250 degrees C and shearing rate up to 125 s(-1). The viscosity showed a max. at 0.7-0.9 s(-1) and at about 170 C. The activation energy of viscous flow was 8.01-8.60 kJ/mol (except for one sample). One of the polyethylenes showed the temp. of transition from high elastic to liq. state at 211.8-225.6 degrees C.