To provide an aqueous polymer composition which is used in the form of a cement grinding aid and makes it possible to effectively reduce the grinding time and to obtain cement exhibiting excellent characteristics and to provide the cement grinding aid containing a combination of a polymer A and the known cement grinding aid.

The aqueous composition comprising at least one polymer A of formula (I) can be used as the cement grinding aid, especially in combination with amino alcohols. A combination of the polymer A with the customary cement grinding aid can remedy or greatly reduce the disadvantages of the known grinding aids without losing the advantageous effects of the polymer A.