Longtan tunnel under construction is a superlong highway tunnel of about 2×8.7km length on Yichang～Enshi section of the national highway from Shanghai to Chengdu. The operation ventilation system of Longtan tunnel requires careful researches. On basis of the actual conditions of the tunnel, a technicallyreliable and costeffective operation ventilation option is determined for the tunnel by means of technic and economic comparisons in terms of ventilation efficiency, disaster prevention, emergency rescue and construction convenience.