The present invention relates to an impeller for an electric water pump capable of preventing a cavitation from occurring in the impeller according to the related art and improving a flow restriction in the impeller by changing an internal structure of the impeller in consideration of a flow of a coolant introduced into the impeller. The impeller for an electric water pump, includes: an inlet member formed in a pipe shape extending to allow a fluid to be introduced; an upper member connected to one end of the inlet member, extending to one side, and having an inner diameter increasing toward the one side; an extension member outwardly extending from one end of the upper member; and a lower impeller member coupled to an upper impeller member formed by the inlet member, the upper member, and the extension member to form a discharge space from which the fluid is discharged.