To open a Doudian store on Alibaba, you need to follow the following steps:

1. Register an Alibaba account: First, you need to register an account on Alibaba's official website. If you already have an account, please skip this step.

2. Log in and enter the Doudian backstage: After logging in to your Alibaba account, click "Doudian" to enter the Doudian backstage.

3. Create a store: In the Doudian backstage, click "Create a store" and fill in relevant information, including store name, category, contact person, etc. Please ensure that the information you fill in is accurate.

4. Complete store information: According to your needs, complete the store information, such as store logo, introduction, contact information, etc.

5. Product management: In the Doudian backstage, you can add products, modify product information, set product categories, etc. Please ensure that the product information is accurate and detailed to attract more consumers.

6. Marketing activities: You can set up marketing activities such as coupons and full reduction activities in the Doudian backstage to attract consumers to buy.

7. Promotion: You can increase the exposure of your store and products through Alibaba's promotion tools, such as Direct Express and Diamond Exhibition.

8. Order management: In the Doudian backend, you can view orders, process orders, ship orders, etc. Please ensure that orders are processed in a timely manner to improve customer satisfaction.

9. After-sales service: Providing consumers with good after-sales service, such as returns, exchanges, refunds, etc., will help improve the store's reputation and credibility.

10. Data analysis: In the Doudian backend, you can view the store's sales data, traffic data, etc., so as to understand the store's operations and optimize operational strategies.

Through the above steps, you can successfully open a Doudian on Alibaba. Please note that opening a Doudian requires compliance with Alibaba's relevant regulations to ensure that the store operates legally and in compliance with regulations.