Legal basis: 202 1 National Natural Science Foundation Project Application and Closing Notice. Article 1 The types of projects accepted in 20021include: general projects, key projects, some major research projects, youth science foundation projects, outstanding youth science foundation projects, national outstanding youth science foundation projects, innovative research group projects, basic science center projects, regional science foundation projects, partial joint fund projects, national major scientific research instrument development projects (free application), mathematical Tianyuan fund projects and key international (regional) projects. Centralized receiving ended on March 20th 16. For other projects other than the above-mentioned project types, the Natural Science Foundation of China will issue a separate guide. For international (regional) cooperation and exchange projects that accept applications at any time, applicants should avoid the centralized acceptance period to submit applications.