Abstract: In the sales contracts of merchandise flats, the two civil rights of property rights and creditors' rights will inevitably be involved. This article analyzes the alteration to property rights in the duplicated sales of merchandise flats, and it points out that a separate principle should be adopted in the alteration of property rights. On the basis of this principle, this paper further analyzes the effect issue in duplicated merchandise flat sales contracts, concluding that the contracts two creditors' rights should both be considered effective. Finally the legal remedy measures for the duplicated sales contracts of merchandise flats are analyzed.