  Based on the distribution of tidal deformabilities and component masses of
binary neutron star merger GW170817, the parametric equation of states (EOS)
are employed to probe the nuclear symmetry energy and the properties of neutron
star. To obtain a proper distribution of the parameters of the EOS that is
consistent with the observation, Bayesian analysis is used and the constraints
of causality and maximum mass are considered. From this analysis, it is found
that the symmetry energy at twice the saturation density of nuclear matter can
be constrained within $E_{sym}(2{\rho_{0}})$ = $34.5^{+20.5}_{-2.3}$ MeV at
90\% credible level. Moreover, the constraints on the radii and dimensionless
tidal deformabilities of canonical neutron stars are also demonstrated through
this analysis, and the corresponding constraints are 10.80 km $< R_{1.4} <$
13.20 km and $133 < \Lambda_{1.4} < 686$ at 90\% credible level, with the most
probable value of $\bar{R}_{1.4}$ = 12.60 km and $\bar{\Lambda}_{1.4}$ = 500,
respectively. With respect to the prior, our result (posterior result) prefers
a softer EOS, corresponding to a lower expected value of symmetry energy, a
smaller radius and a smaller tidal deformability.
