  We propose a versatile and accurate method to estimate the halo mass and
concentration from the kinematics of satellite galaxies. We construct the 6D
phase-space distribution function of satellites from a cosmological simulation
based on the similarity of internal dynamics for different halos. Within the
Bayesian statistical framework, not only can we infer the halo mass and
concentration efficiently, but also treat various observational effects,
including the selection function, incomplete data, and measurement errors, in a
rigorous and straightforward manner. Through tests with mock samples, we show
that our method is valid and accurate, and more precise than pure steady-state
methods. It can constrain the halo mass to within ~ 20% using only 20 tracers
and has a small intrinsic uncertainty of ~ 10%. In addition to the clear
application to the Milky Way and similar galaxies, our method can be extended
to galaxy groups or clusters.
