On the basis of different protective targets, optimal tariff can be classified into optimal welfare tariff and maximum revenue tariff. If a country itself produces a product and imports another product, the quality of the two products is different, we can analyze the issue of optimal welfare tariff and maximum revenue tariff, the analysis results show that, on the one hand, if the domestic product quality is relatively lower but the imported product quality is higher, no matter Bertrand competition or Cournot competition the enterprises conduct, then maximum revenue tariff is larger (smaller) than optimal welfare tariff if foreign enterprise efficiency is higher (lower), furthermore, the optimal welfare tariff and maximum revenue tariff under Cournot competition condition are higher than optimal welfare tariff and maximum revenue tariff under Bertrand competition condition respectively; on the other hand, if domestic product quality is higher but the imported product quality is lower, then maximum revenue tariff is higher (lower) than optimal welfare tariff if domestic enterprise efficiency is lower (higher).