  In this article we investigate the entanglement behavior of quantum states of
fermionic system in accelerated frame. It was known that unlike scalar case the
entanglement of fermionic maximally entangled states survives even in the
infinite acceleration limit. Also for the fermionic system it was discussed
that one may consider the approach beyond single mode approximation. However
due to the peculiar property of fermionic system there has been different
opinions about correct physical structure of fermionic system. Recently Montero
and Mart\'{i}n-Mart\'{i}nez suggested an approach beyond single mode
approximation. Using the structure proposed by Montero and
Mart\'{i}n-Mart\'{i}nez we investigate the entanglement behavior of quantum
states of fermionic system in accelerated frame. We find that the approach by
Montero and Mart\'{i}n-Mart\'{i}nez seems to work appropriately. Also we may
obtain the proper entanglement behavior of quantum states in fermionic system
in accelerated frame(our result may correct the previous results published in
Phys.Rev.A 83 052306).
