Numerous check dams have been constructed in many countries,but there continues to be very limited scientific evidence of their effect on biotic community.Since amphibians are highly sensitive to moisture changes,amphibian assemblages were used as a monitoring parameter to evaluate the effects of check dams on biotic components in this study.Comparison of amphibian assemblages between check dam and non-check dam areas was conducted along ephemeral streams in a tropical deciduous forest of the Chulalongkom University Forest and Research Station in Nan Province,Thailand from April 2009 to March 2010.Five transects,including the stream transect,and 5,10,25,and 50 m terrestrial transects,were used for amphibian surveys between the two areas.Physical factors related to moisture were also compared between these areas.It was found that hydroperiod in the check dam stream was significantly higher than that in the non-check dam stream.Soil moisture content at most terrestrial transects in the check dam area was significantly higher than that in the non-check dam area,while similarity in leaf litter moisture content was found in most transects.Simpson's index of diversity indicated that amphibian diversities in all transects were equally diverse between the two areas in both wet and dry seasons.Cluster analysis of similarity in species composition indicated that amphibian composition in the check dam stream was distinct from that in the non-check dam stream in the wet season or the functional period of the check dam.However,the amphibian compositions in both check dam and non-check dam streams were similar to each other in the dry season.No significant check dam effect was found on species composition in the terrestrial habitats in both seasons.Overall,using a highly moisture-sensitive vertebrate as a bio-indicator,the results showed that the check dams and the changes in moisture-related physical factors appear to have little short-term effect on amphibian assemblages.