An LED lamp for lighting purpose includes a lamp base, a heat sink, a plurality of LED modules and a blower. The lamp base encloses an inner space and defines a plurality of vents therein. The vents communicate the inner space with a surrounding atmosphere. The heat sink comprises a cylinder at a center thereof. The cylinder has a through hole therein, which communicates with the inner space and vents of the lamp base and cooperates therewith to form an air passage. The LED modules are attached to a periphery of the heat sink. The blower generates an airflow circulating through the air passage to thereby dissipate heat generated by the LED modules.