Fungal biofilm formation and its regulatory mechanism Fungal biofilms are microbial communities composed of fungal cells and extracellular polymeric substances (EPS). Recent studies have shown that fungal biofilms play an increasingly important role in various fields. However, research on fungal biofilms and their applications is still limited. This review summarizes the composition and function of EPS in fungal biofilms, improves and refines the formation process of fungal biofilms according to the latest viewpoints, and summarizes the gene regulation network of fungal biofilm synthesis based on studies of Saccharomyces cerevisiae and Candida albicans. This is crucial for understanding the molecular mechanism of fungal biofilm formation. It is of great significance to develop effective methods at the molecular level to control harmful biofilms or enhance and regulate the formation of beneficial biofilms. The review also summarizes quorum sensing factors and mixed biofilms formed by fungi in current research on fungal biofilms. These results will help deepen the understanding of the formation process and internal regulation mechanism of fungal biofilms, provide references for the study of EPS composition and structure, formation, regulation, group behavior, and mixed biofilm formation of other fungal biofilms, and provide strategies and theoretical basis for the control, development, and utilization of fungal biofilms. Fungal biofilm formation is a multi-stage process, and it can be categorized into yeast cell biofilms and hyphal biofilms based on whether or not they contain hyphae. The formation of fungal biofilm consists of four stages: interfacial adhesion, growth, maturation, and dispersion. The first step in the process of fungal biofilm formation is adhesion at the interfacial surface, which is the basic condition for biofilms to acquire external nutrients. In this stage, fungal cells synthesize sugars, proteins, and lipids to increase cell adhesion and promote adhesion or aggregation. However, there is growing evidence that biofilms do not necessarily require surface attachment to form, and that aggregates can form in fluids induced by asexual growth, co-aggregation, or host fluids. With the continuous growth and expansion of the biofilm, the biofilm will enter the mature stage. The most obvious sign of mature biofilm is the formation of three-dimensional structure, which is closely related to the production of EPS. These components are interconnected to polymerize cells, making the colony present a special appearance structure and enhancing the stability of the biofilm. Biofilm dispersion is the final stage of the biofilm life cycle and the beginning of another life cycle. Biofilm dispersion is divided into initiative dispersion and passive dispersion, and the former is characterized by the promotion of dispersion through gene regulation, which is mainly manifested in the inhibition of fungal production of extracellular matrix, the promotion of the production of enzymes that degrade extracellular components, and the enhancement of cellular motility, which facilitates the diffusion of planktonic cells to the surrounding environment. Passive dispersion, also known as environmentally induced dispersalFungal biofilm formation and its regulatory mechanism Fungal biofilms are microbial communities composed of fungal cells and extracellular polymeric substances (EPS). Recent studies have shown that fungal biofilms play an increasingly important role in various fields. However, research on fungal biofilms and their applications is still limited. This review summarizes the composition and function of EPS in fungal biofilms, improves and refines the formation process of fungal biofilms according to the latest viewpoints, and summarizes the gene regulation network of fungal biofilm synthesis based on studies of Saccharomyces cerevisiae and Candida albicans. This is crucial for understanding the molecular mechanism of fungal biofilm formation. It is of great significance to develop effective methods at the molecular level to control harmful biofilms or enhance and regulate the formation of beneficial biofilms. The review also summarizes quorum sensing factors and mixed biofilms formed by fungi in current research on fungal biofilms. These results will help deepen the understanding of the formation process and internal regulation mechanism of fungal biofilms, provide references for the study of EPS composition and structure, formation, regulation, group behavior, and mixed biofilm formation of other fungal biofilms, and provide strategies and theoretical basis for the control, development, and utilization of fungal biofilms. Fungal biofilm formation is a multi-stage process, and it can be categorized into yeast cell biofilms and hyphal biofilms based on whether or not they contain hyphae. The formation of fungal biofilm consists of four stages: interfacial adhesion, growth, maturation, and dispersion. The first step in the process of fungal biofilm formation is adhesion at the interfacial surface, which is the basic condition for biofilms to acquire external nutrients. In this stage, fungal cells synthesize sugars, proteins, and lipids to increase cell adhesion and promote adhesion or aggregation. However, there is growing evidence that biofilms do not necessarily require surface attachment to form, and that aggregates can form in fluids induced by asexual growth, co-aggregation, or host fluids. With the continuous growth and expansion of the biofilm, the biofilm will enter the mature stage. The most obvious sign of mature biofilm is the formation of three-dimensional structure, which is closely related to the production of EPS. These components are interconnected to polymerize cells, making the colony present a special appearance structure and enhancing the stability of the biofilm. Biofilm dispersion is the final stage of the biofilm life cycle and the beginning of another life cycle. Biofilm dispersion is divided into initiative dispersion and passive dispersion, and the former is characterized by the promotion of dispersion through gene regulation, which is mainly manifested in the inhibition of fungal production of extracellular matrix, the promotion of the production of enzymes that degrade extracellular components, and the enhancement of cellular motility, which facilitates the diffusion of planktonic cells to the surrounding environment. Passive dispersion, also known as environmentally induced dispersal