  We study the localization of fermions in an anisotropic random magnetic field
in two dimensions. It is assumed that the randomness in a particular direction
is stronger than those in the other directions. We consider a network model of
zero field contours, where there are two types of randomness - the random
tunneling matrix element at the saddle points and unidirectional random
variation of the number of fermionic states following zero field contours.
After averaging over the random complex tunneling amplitude, the problem is
mapped to an SU(2N) random exchange quantum spin chain in the $N \to 0$ limit.
We suggest that the fermionic state becomes critical in an anisotropic fashion.
