The present invention relates to a pulsation reducer which includes: an entrance-expanded fuel rail (40) configured such that a section-expanded fuel rail entrance (41) expanded to the size of the section of a high-pressure fuel line (31) is foiled thereon; a spring housing (61) configured such that a fuel storage space (611) and a low-pressure movement space (613) and high-pressure movement space (614) connected to the fuel storage space (611) via chimney holes (612a and 612b) are formed therein; connection parts (62a, 62b and 62c) configured to connect the spring housing 61 with the entrance-expanded fuel rail (40); a low-pressure reduction part (631) disposed in the low-pressure movement space (613), and configured to absorb mixed pulse waves in a low-pressure region; and a high-pressure reduction part (64) disposed in the high-pressure movement space (614), and configured to absorb mixed pulse waves in a high-pressure region.