  We compile from literature the broadband SEDs of twelve TeV blazars observed
simultaneously or quasi-simultaneously with Fermi/LAT and other instruments.
Two SEDs are available for each of the objects and the state is identified as a
low or high state according to its flux density at GeV/TeV band. The observed
SEDs of BL Lac objects (BL Lacs) are fitted well with the synchrotron +
synchrotron-self-Compton (syn+SSC) model, whereas the SEDs of the two flat
spectrum radio quasars (FSRQs) need to include the contributions of external
Compton scattering. In this scenario, it is found that the Doppler factor delta
of FSRQs is smaller than that of BL Lacs, but the magnetic field strength B of
FSRQs is larger than that of BL Lacs. The increase of the peak frequency of the
SEDs is accompanied with the increase of the flux for the individual sources,
which seems opposite to the observational phenomena of the blazar sequence. We
refer this phenomenon to blazar anti-sequence of spectral variability for
individual TeV blazars. However, both the blazar sequence from FSRQs to BL Lacs
and blazar anti-sequence of the spectral variability from low state to high
state are accompanied by an increase of the break Lorentz factor of the
electron's spectrum gamma_b and a decrease of B. We propose a model in which
the mass accretion rate is the driving force behind both the blazar sequence
for ensembles of blazars and the blazar anti-sequence for individual blazars.
Specifically we suggest that the differences in mass accretion rate of
different blazars produce the observed blazar sequence, but \Delta M in each
blazar results in the observed blazar anti-sequence.

High Energy Astrophysical Phenomena