Abstract: A lamp comprises a housing, a heat sink, a light emitting member, a fan and a blocking ring. The housing includes an outlet section and an inlet section formed on the wall thereof. The heat sink is mounted inside the housing and includes a base plate and a plurality of fins, with the fins being close to the outlet section of the housing and arranged around the base plate to form a chamber. Each of the fins has a first end facing the inlet section of the housing and a second end connecting with the base plate. The light emitting member is fixed to the base plate of the heat sink. The fan is fixed inside the chamber of the heat sink. The blocking ring is mounted inside the housing and between the inlet section and the heat sink and includes an inlet hole aligned with the chamber of the heat sink. By the blocking ring, parts of the heated air flows are blocked from flowing back to the inlet section to avoid turbulence resulting from flowing back air flows.