  By fitting high-quality and simultaneous multi-wavelength (MWL) spectral
energy distributions (SEDs) at multiple epochs with a one-zone leptonic jet
model, we study jet properties of the three famous blazars Mrk 421, 3C 454.3
and 3C 279. In the jet model, the emitting electron energy distributions (EEDs)
are calculated by solving the kinetic equation of electron injection, escape,
adiabatic and radiative energy losses. To explore multi-dimensional parameter
space systematically, we employ a Markov chain Monte Carlo (MCMC) fitting
technique. The properties of emission regions we derived here are consistent
with those in previous studies, e.g., the particle-dominated and
low-magnetization jet. The new finding is that there is a tight correlation
between $\gamma$-ray luminosity and electron injection power and an
anti-correlation between $\gamma$-ray luminosity and jet magnetization
parameter. The results suggest that same energy-dissipative mechanism (like a
shock) could be operating in the jets of different types of blazars, and the
origin of $\gamma$-ray flares is associated with the particle acceleration
process.
