Formation of a group of sand spits on lakeshore was investigated in Lake Saroma in eastern Hokkaido. Several sand spits develop by longshore sand transport generated by wind waves in eastern part of slender shape of this lake. Wild flower park is located in this area, but recently seawalls to protect cycling road against lakeshore erosion were built, which kill scenic beauty of natural lakeshore. The cause is due to the approximation of cycling road to the shoreline, which is changing responding to the movement of sand spits. In order to improve this condition appropriate setback is needed.