Various steam seals have their own features, of which new types substituting for traditional ones has already become a trend. The structures and sealing mechanisms are introduced and the steam seals compared including serrate type, cellular type, lateral teeth type and Brighton steam seals. During the reconstruction of 2 unit in the State Power Generation Co., Ltd. Tongling, the lateral teeth type and cellular type steam seals are applied, and the actual operating conditions are analyzed. Furthermore, the influences of various types of steam seals on the safe and economic operation of steam turbine and energy saving are discussed. It is shown that the safety, tightness and economy are prominent by the reconstruction of steam seals.