  We confront tracker field quintessence with observational data. The
potentials considered in this paper include $V(\phi)\propto\phi^{-\alpha}$,
$\exp(M_{p}/\phi)$, $\exp(M_{p}/\phi)-1$, $\exp(\beta M_{p}/\phi)$ and
$\exp(\gamma M_{p}/\phi)-1$; while the data come from the latest SN Ia, CMB and
BAO observations. Stringent parameter constraints are obtained. In comparison
with the cosmological constant via information criteria, it is found that
models with potentials $\exp(M_{p}/\phi)$, $\exp(M_{p}/\phi)-1$ and
$\exp(\gamma M_{p}/\phi)-1$ are not supported by the current data.
