In this paper,we generally summarize the main issues in the operational period of water conservancy and hydropower projects in China over the past several decades.First,the adverse impacts of these projects since the technical guidelines were proposed in 2006 are analyzed.Then,combined with projects and experience from 2006 to 2014,the four main issues are summarized:(1) There exist many questions in the design and construction of fishways,which are useful for fish migration,and the migration effects are not as expected.(2) Temperature stratification affecting the downstream fish is the major impact of temperature,and alters fish spawning in the reproduction season.(3)Ecological base flow has been one of the primary questions of the last 30 years in China,the greatest related difficulty being quantification of the amount and flow process necessary to satisfy fish life history.(4) Fish habitat protection and restoration are popular topics in recent years with the development of river ecosystem restoration.Fish habitat loss due to the impacts of dam construction and habitat fragmentation has become more and more serious.These four issues are now the main difficulties in water project management,and interact with one another to bear combined effects on river ecosystems.The issues of eco-hydraulic consideration in the design period are the key factors.Finally,future priorities for research and practice of environmental protection for water conservancy and hydropower projects in China are proposed.The main purpose of this paper is to enhance the scientific research,monitoring,and assessment of operating effectiveness. In this paper, we generally summarize the main issues in the operational period of water conservancy and hydropower projects in China over the past several decades. First, the adverse impacts of these projects since the technical guidelines were proposed in 2006. Are assembled. with projects and experience from 2006 to 2014, the four main issues are summarized: (1) There exist many questions in the design and construction of fishways, which are useful for fish migration, and the migration effects are not as expected. (2) Temperature stratification affecting the downstream fish is the major impact of temperature, and alters fish spawning in the sale season. (3) Ecological base flow has been one of the primary questions of the last 30 years in China, the greatest related difficulty being quantification of the amount and flow process necessary to satisfy fish life history. (4) Fish habitat protection and restoration are popular topics in recent years with the development of river ec osystem restoration.Fish habitat loss due to the impacts of dam construction and habitat fragmentation has become more and more serious. these four issues are now the main difficulties in water project management, and interact with one another to bear combined effects on river ecosystems.The issues of eco-hydraulic consideration in the design period are the key factors .Finally, future priorities for research and practice of environmental protection for water conservancy and hydropower projects in China are proposed. The main purpose of this paper is to enhance the scientific research, monitoring, and assessment of operating effectiveness.