Microalgae possess strong selenium-enriched capabilities,and its selenium-enriched products have both selenium and biological activities of microalgae.Researching and cultivating selenium-enriched microalgae can not only improve the nutritional value and commercial value of microalgae itself,but also improve the quality of food and feed containing microalgae and play a good health effect.This paper overviews the effects of selenium on the growth rate and nutrient content of microalgae,analyzes the influencing factors of selenium enrichment in microalgae,common selenium-enriched microalgae species and their inter-species differences,as well as the existing forms and transformation pathways of selenium in microalgae.The focus is to summarize the current status and potential development of selenium-enriched microalgae applications in food,feed,pharmaceuticals,environmental protection,and monitoring.This review aims to provide a theoretical basis for the development of selenium-enriched microalgae products and offer insights into cultivating high-quality,high-yield selenium-enriched microalgae.