Ecohydrology is a new and developing frontier science for nearly 20 years

which studies the interrelation between hydrology and ecology on the watershed scale

and seeks the new approach to ecological balance and sustainable utilization of water resources in watershed. Now the ecohydrology has been paid great attention in academic circles in China

but the research is just on its beginning stage. Internationally

although many studies have been carried out

especially in the United States

Europe and Canada

but there are still divergences for some basic problems

such as the definition of ecohydrology. Ecohydrology and some relevant concepts are reviewed and discussed briefly in this paper

including the definition of ecohydrology

ecosystem approach

habitat quality and its composition

environmental factors affecting biological integrity

analytical approaches

and concepts in river ecology. The purpose is to deepen the knowledge of ecohydrology.