  The very small braking index of PSR J1734-3333, $n=0.9\pm0.2$, challenges the
current theories of braking mechanisms in pulsars. We present a possible
interpretation that this pulsar is surrounded by a fall-back disk and braked by
it. A modified braking torque is proposed based on the competition between the
magnetic energy density of a pulsar and the kinetic energy density of a
fall-back disk. With this torque, a self-similar disk can fit all the observed
parameters of PSR J1734-3333 with natural initial parameters. In this regime,
the star will evolve to the region having anomalous X-ray pulsars and soft
gamma repeaters in the $P-\dot{P}$ diagram in about 20000 years and stay there
for a very long time. The mass of the disk around PSR J1734-3333 in our model
is about $10M_{\oplus}$, similar to the observed mass of the disk around AXP 4U
0142+61.
