2021 International Symposium on Environmental Engineering and Microbiology (ISEEM 2021) will on May 13, 2021 (Online Conference). As the 3rd International Conference on Biofilms(Asia-Pacific Biofilms 2021), the conference venue will be set in South China University of Technology along with the main conference. The symposium will be hosted by South China University of Technology and Southern University of Science and Technology,and organized by AEIC Academic Exchange Information Center. ISEEM 2021 will invite well-known scholars to give keynote speeches or guest lectures on related topics such as environmental engineering and microbiology, and invite young scientists from various disciplines with the latest research achievements to give oral speeches. It provides an international platform for experts, scholars, engineers and R&D personnel in this field to share professional experience, expand professional network, exchange new ideas face to face and display research results.