Small hydropower is one of the effective renewable energies. Based on the authors' past research of Darrieus-type hydro-turbine with inlet nozzle, a portable Darrieus-type hydro-turbine has been developed to be applied for side gutter flows. In the present study, experimental investigations are carried out in order to examine the effects of slope of rectangular channel on turbine performances. As a result, in the sloped channels, the hydraulic jump from the super to subcritical flows is observed upstream of the turbine, whereas the non-dimensional turbine performances are not very affected by the slope of the channel. The power and head coefficients are larger at the lower flow rate, but the maximum turbine efficiency takes similar value regardless of the flow rate.