Recent x-ray observations revealed that strong cooling flow of intracluster gas is not present in galaxy clusters, even though it is predicted theoretically if there is no additional heating source. I show that relativistic particles produced by dark matter neutralino annihilation in cluster cores provide a sufficient heating source to suppress the cooling flow, under reasonable astrophysical circumstances including adiabatic growth of central density profile, with appropriate particle physics parameters for dark matter neutralinos. In contrast to other astrophysical heat sources, such as active galactic nuclei, this process is a steady and stable feedback over cosmological time scales after turned on.