  We suggest a model of the advection dominated accretion flow (ADAF) with
magnetically driven outflows to explain hysteretic state transition observed in
X-ray binaries (XRBs). The transition from a thin disk to an ADAF occurs when
the mass accretion rate is below a critical value. The critical mass accretion
rate for the ADAF can be estimated by equating the equilibration timescale to
accretion timescale of the ADAF, which is sensitive to its radial velocity. The
radial velocity of thin disks is very small, which leads to the advection of
the external field in thin disks very inefficient. ADAFs are present in the
low/hard states of XRBs, and their radial velocity is large compared with the
thin disk. The external field can be dragged inward efficiently by the ADAF, so
a strong large-scale magnetic field threading the ADAF can be formed, which may
accelerate a fraction of gas in the ADAF into the outflows. Such outflows may
carry away a large amount of angular momentum from the ADAF, which increases
the radial velocity of the ADAF significantly. This leads to a high critical
mass accretion rate, below which an ADAF with magnetic outflows can survive.
Our calculations show that the critical luminosity of the ADAF with magnetic
outflows can be one order of magnitude higher than that for a conventional
ADAF, if the ratio of gas to magnetic pressure $\beta\sim 4$ in the disk. This
can naturally explain the hysteretic state transition observed in XRBs.
