PURPOSE: To provide a pulsation reducer for a hydraulic pump capable of suppressing the generation of noise by reducing the pulsation of pressure oil discharged from the hydraulic pump in a hydraulic circuit.

CONSTITUTION: A branch line 11 is provided being connected to a first line 4, communicating a hydraulic pump 1 with a direction switching valve 2 in a hydraulic circuit, with one end side connected to the first line 4 in a position Y upstream on the hydraulic pump 1 side and with the other side connected to the first line 4 in a position X downstream of the position Y. The length of this branch line 11 is so set as to generate wavelength of approximately half the wavelength of pressure pulsation of pressure oil discharged from the hydraulic pump 1. The pressure pulsation of pressure oil discharged from the hydraulic pump l is transmitted also to the branch line 11, and since the waveform is shifted by an approximately half cycle, pulsation is nullified by the confluence of both so as to reduce pressure pulsation.