We studied temporal effects of slit installation on a check dam on stream habitat and macroinvertebrates in the Wasada River located at Yamagata Prefecture in Japan. Quantitative sampling of benthic macroinvertebrates and measurement of channel morphology were carried out at the inlet and outlet sites of the two check dams in the studied river more than once per year through 2009 to 2015. The dam at downstream was slit in August 2010. The channel morphology was measured using a high precision Global Position System (GPS) and classified into 7 habitat types (e.g., riffle and pool), which was subsequently used for calculating habitat diversity. As results, while the habitat diversity increased at the inlet site of the slit dam after the slit event, species diversity of benthic macroinvertebrates did not display any trends over time. This may suggest that, at least within a few years, local habitat diversification would only result in a fraction of contribution to species diversity. We observed significant negative correlation between the species diversity and the ratio of lentic habitat (R²=0.35, P<0.05) in contrast to an earlier study, indicating that increase in lentic habitat at a given stream (or reach) might diminish species diversity of stream macroinvertebrates.