  Recently, Majorana Fermions (MFs) have attracted intensive attention due to
their exotic statistics and possible applications in topological quantum
computation (TQC). They are proposed to exist in various two-dimensional (2D)
topological systems, such as px+ipy topological superconductor and
nanowire-superconducting hybridization system. In this paper, two types of
Majorana Fermions with different polygon sign rules are pointed out. A "smoking
gun" numerical evidence to identify MF's classification is presented through
looking for the signature of a first order topological quantum phase
transition. By using it, several 2D topological superconductors are studied.
