A hood retaining structure for a heat-dissipating device. The heat-dissipating device includes a heat sink with at least one heat-dissipating fin set, and each heat-dissipating fin set includes a plurality of heat-dissipating fins erected vertically. The hood retaining structure is arranged on the heat-dissipating fins to retain a hood thereon and a fan is able to retain to the hood. The hood retaining structure includes a dent defined on an outer side of each heat-dissipating fin such that a retaining groove is defined after the heat-dissipating fin are assembled and at least one retaining rod and at least one retaining hook provided on lateral sides of the hood, the retaining rod and the retaining hook being configured to lock into the retaining groove. The retaining hook includes a push tab.