  We present a determination of the strange, charm and bottom quark masses as
well as the strong coupling constant in 2+1 flavor lattice QCD simulations
using highly improved staggered quark action. The ratios of the charm quark
mass to the strange quark mass and the bottom quark mass to the charm quark
mass are obtained from the meson masses calculated on the lattice and found to
be $m_c/m_s=11.871(91)$ and $m_b/m_c=4.528(57)$ in the continuum limit. We also
determine the strong coupling constant and the charm quark mass using the
moments of pseudoscalar charmonium correlators: $\alpha_s(\mu=m_c)=0.3697(85)$
and $m_c(\mu=m_c)=1.267(12)$ GeV. Our result for $\alpha_s$ corresponds to the
determination of the strong coupling constant at the lowest energy scale so far
and is translated to the value $\alpha_s(\mu=M_Z,n_f=5)=0.11622(84)$.
