Limnology is a multidisciplinary and integrative science studying inland waters, having a history of nearly 130 years since Francois Alphonse Forel defined it firstly in 1892. The main subdisciplines include geological limnology (including paleoplimnology), physical limnology, chemical (biogeochemical) limnology and biological limnology. The key feature of limnology is the interdisciplinary nature that is achieved by integrating different disciplines to synthesize the process and mechanisms at the level of the ecosystem, and to predict the ecosystem changes. Therefore, limnology is the key science supporting the protection, management and restoration of inland water ecosystems and water resources. However, the development of limnology in China is faced with the problems such as unbalanced development in subdisciplines and fragmentation in researches. The effects of increased human activities and global changes on inland waters are the challenges and opportunities for limnological researches. The main research topics in China need to focus on the effects of human activities and global changes on inland waters, including: 1) the changes in hydrodynamics and hydromorphology and their ecological and environment effects; 2) nutrient and organic matter biogeochemical cycling and the associated ecological and environment effects; 3) structures and functioning of food webs; 4) impacts of invaded species and managements; 5) the control of water associated diseases; 6) ecological quality assessments of surface waters; 7) ecosystem evolution and the mechanisms, and restoration of degraded ecosystems.