Ensemble studies have contributed tremendously to comprehending biological reactions. However, these studies characterize the average molecular population, and have limited ability to detect intermediate states or to distinguish heterogeneities. Over the past few decades, single-molecule techniques, including fluorescence resonance energy transfer (FRET), magnetic tweezers (MT) and optical tweezers (OT), have proved to be exceedingly powerful in addressing this knowledge gap. By studying one molecule at a time, these approaches have enabled significant advancement in understanding a wide variety of biomolecular systems, especially those involving nucleic acids and associated proteins. Using these single‐molecule techniques, our research has focused on understanding mechanisms and functions of molecular motors, such as helicase, polymerase and nuclease, in the processes of DNA replication, repair, recombination, editing, and segregation and on developing technological innovations to meet the challenges in the pursuits. We are also interesed in membraneless organelles and amyloid fibrils related to neurodegenerative diseases. Currently, our lab covers five research fields: