An optical transceiver having a effective heat conducting path from the TOSA to the metal housing is disclosed. The TOSA has a bottom member, on which a heat generating device such as TEC is mounted, extending to a direction perpendicular to the longitudinal axis of the metal housing. The optical transceiver further includes a block movably in contact with the bottom member of the TOSA and the inner surface of the metal housing to establish the effective heat conducting path from the TOSA to the metal housing.