In this paper we discuss different Subtracters design based on quantum dot cellular automata (QCA). QCA is an emerging nanotechnology for electronic circuits. It has the potential for attractive features such as faster speed, smaller size and low power consumption than transistor based technology. By taking the advantages of QCA we are able to design interesting computational architectures. The Subtracters: Half-Subtractor and Full-Subtractor are designed and simulated using QCA Designer. The QCA designer is a design and simulation tool for quantum dot cellular automata (QCA).