This paper analyzes the optimal uniform and discriminatory quality requirements under Cournot and Bertrand competition when two firms produce high, and low, quality products respectively in a domestic market. We find that under uniform and discriminatory quality requirements, the government's optimal quality requirement depends on the type of competition in which firms engage. When discriminatory quality requirements are adopted, the government should ask both high and low quality firms to raise their quality standard under Bertrand competition and decrease the quality differentiation. However, the government should ask the high quality and low quality firm to raise and lower their quality respectively and increase the quality differentiation under Cournot competition. When uniform quality requirement is adopted, the government should set a quality requirement raising both firms' quality respectively under Bertrand competition, and the low quality firm will produce at the lowest quality standard, while under Cournot competition the government should not set any quality requirement. In addition to premium agricultural products seal, our results also provide useful strategic recommendations for the government's quality policy.