PURPOSE: To obtain in high yield a polyketone suited for use in an engineering resin.

CONSTITUTION: A process for continuously producing a polyketone by polymerizing ethylene and carbon monoxide in a diluting solvent in the presence of a radical-polymerization initiator which process comprises blowing a gaseous mixture of the monomers into the solvent under such conditions that Q/(P.V0) is 0.005-0.2 [wherein Q (1/min) is the feed rate for the mixture in the standard state; P (kgfcm-2 G) is polymerization pressure; and V0 (liter) is the volume of the solvent].