In order to reveal the influence of dams in Luanhe River basin to hydrologic in downstream and analyze its ecological effects, water ecological effects evaluation system of dam effects in river basin was developed. RVA method was also used to assess the ecological effects of Panjiakou dam. The results are as follow: (1)The degree of impact by each dam: Panjiakou>Taolinkou>Shandianhe>Miaogong. The hydrologic impact by dams is influenced by both capacity and natural river flow. (2)Index of IHA river flow change(measured with RVA method)in Panjiakou Reservoir is 0. 88. Classes 1-2 of IHA indexes are highly changed, which is 0. 91, and classes 3-5 are moderately changed, which is 0. 45. Dams influenced fish migration, benthos, and riparian vegetation of the basin. Ecological and hydrological co-monitoring and modelling development would be helpful to improve the warning ability of river ecosystem, and provide scientific basis and technical tools for river ecological restoration.