Abstract: Microalgae are rich in various active substances，such as pigments，fatty acids，polysaccharides，sterols，proteins and others. Existing research shows that it has regulation of human immune，antioxidant，anti⁃inflammatory，and anti⁃virus，etc. It is considered to be natural health food and medicine⁃derived food. This article reviews the functions of China's main industrialized microalgae and their active substances. The main contents include the composition，structural characteristics，functions of regulating human immunity，and antiviral functions of inhibiting viral replication and viral pathology. This article will provide a certain reference for the development and utilization of microalgae and their active substances and the study of their precise functions.

Key words: microalgae, active material, antiviral, immune regulation