  We investigate the physical properties of BL Lac objects (BL Lacs) jets by
modeling the quasi-simultaneous spectral energy distributions (SEDs) of 22 {\it
Fermi} BL Lac objects in the frame of a simple one-zone synchrotron
self-Compton (SSC) model. We obtained the best-fit model parameters and their
uncertainties for each BL Lac object through the $\chi^2$-minimization
procedure and discussed their implications on the physical processes. The
modeling results show that the one-zone SSC model can successfully fit the SEDs
of high-synchrotron-peaked BL Lacs (HBLs) and intermediate-synchrotron-peaked
BL Lacs (IBLs), but fails to explain the SEDs of low-synchrotron-peaked BL Lacs
(LBLs). The statistical analysis results for model parameters are summarized as
follows. (1) No correlation is found between magnetic field ($B$) and the
broken energy of relativistic electrons distribution ($\gamma^{\prime}_{\rm
b}$) for HBLs and IBLs, but there are inverse correlations between
$\gamma^{\prime}_{\rm b}$ and the radius of emitting blob ($R^{\prime}_{\rm
b}$) as well as the electrons number $K^{\prime}_{\rm e}$ for HBLs and IBLs.
It's therefore concluded that the variation of $\gamma^{\prime}_{\rm b}$ is
mainly caused by that of $R^{\prime}_{\rm b}$ rather than $B$ for HBLs and
IBLs. (2) The Poynting flux in jets can not account for the observed radiations
since the power in Poynting flux is smaller than the radiative power, and the
cold protons could be the primary energy carrier in the jets.
