A high performance fluorescent lamp includes an air-vacuum glass envelope having sealed ends, and a light cavity filled with inert gas and coated with a phosphor layer at an inner wall of said light cavity; two electrodes sealed at each of the sealed ends of the glass envelope; and a narrowing channel integrally formed at one of the sealed ends of the glass envelope at a location communicating with the light cavity of the glass envelope. Therefore, the amalgam is contained within the narrowing channel at a position forming a preset distance between one of the electrodes sealed at the corresponding sealed end and the amalgam.