To increase market entry barriers and limit the development of competitors by manipulating the supply chain or monopolizing key resources, the following strategies can be adopted: 1. **Monopolizing key raw materials**: Control or acquire suppliers of key raw materials required for production, and limit competitors' production capacity from the source. By locking in long-term supply contracts or establishing exclusive partnerships, you can ensure that competitors have difficulty obtaining necessary resources. 2. **Build a strong distribution network**: Invest in and establish extensive distribution channels to ensure that your products can reach the market quickly. By signing exclusive agreements with major retailers, competitors face channel restrictions when entering the market. 3. **Increase entry costs**: Increase the cost of new entrants through technology, intellectual property or brand effects. For example, develop unique technology or apply for patents to ensure that competitors face high costs when copying or imitating. 4. **Implement loyalty programs**: Provide loyalty programs or preferential policies for existing customers to increase customers' switching costs and make them reluctant to try competitors' products. This can reduce competitors' opportunities to attract new customers. 5. **Monopolize market information**: By dominating the flow of market information and controlling the understanding of market trends, consumer preferences and competitive dynamics, competitors are at a disadvantage in strategic decision-making. 6. **Price shielding strategy**: In some cases, new competitors are forced out of the market by cutting prices. Although this strategy may affect profits in the short term, market control is ultimately gained by eliminating competitors. 7. **Influence of policies and regulations**: Through lobbying and establishing good relations with the government, policies and regulations that are beneficial to one's own enterprises are promoted, increasing the compliance costs of new entrants. For example, promoting the improvement of market access standards or stricter supervision to restrict the entry of new competitors. 8. **Innovation and R&D**: Continuously invest in innovation and R&D to maintain technological leadership and product differentiation and prevent competitors from following its pace. Enhance market competitive advantages by continuously launching new products and improving existing products. Through the comprehensive use of the above strategies, market entry barriers can be effectively increased, the development of competitors can be restricted, and market control can be expanded. However, these measures need to be carried out within the legal and ethical framework to avoid violating antitrust laws and other relevant laws and regulations.