Abstract: The local scour caused by a pile on a slope differs to that at the flat sand bed. A 1:16 slope with sediment median size of 0.32 mm was set up, and an experimental study of local scour around the pile under the action of regular wave was conducted. Under the condition of small KC number, effect of wave height, wave period and pile position were discussed, and similarities and differences between local scour on the slope and at the flat were compared and analyzed from two aspects of maximum scour depth and scour profiles. It is shown from experimental results that the pile position at the slope brings a great influence to the local scour character; Under the same KC number, the maximum scour depth on the slope is greater than that at the flat sand bed; A distinguishing profile is displayed between clear-water scour on the slope and at the flat sand bed, but no obvious distinction is exhibited during muddy-water scour.