Bacterial biofilm is a very complex structure with diverse bacterial cells in a highly organized and ordered group within a matrix of extracellular polymeric substances that they produce. Microbes attach to surfaces in order to develop biofilms, which is a sophisticated process regulated by factors such as nutritional status and biotic/abiotic surface features, etc. An established biofilm structure is mainly composed of bacterial cells, proteins, nucleic acid, and exo-polysaccharides (EPS) that are extracellular macromolecules excreted as a tightly bound layer in microbes, which provides a perfect niche for bacteria to exchange genetic material between cells. In addition, bacterial cells in the matrix also communicate via quorum sensing, which has a great impact on biofilm processes. Under clinical circumstances, bacterial biofilm shows great resistance to antibiotics, disinfectants, and also body defense systems, which makes it very difficult to eradicate for clinicians and facilitates many infectious disease processes, leading to chronic infections of patients with long-term hospitalization and high mortality. Therefore, it is very important to understand the recent advances in the formation, regulation, and eradication of biofilms in human infections in order to get better prevention, control, and treatment of biofilm infections in human beings. Written by an international team of basic and clinical researchers, the chapters of this book would provide novel insights and advanced knowledge for life science researchers, clinical researchers and doctors, and all interested readers on some latest developments in the biofilm field.