  We use the Radial Baryon Acoustic Oscillation (RBAO) measurements, distant
type Ia supernovae (SNe Ia), the observational $H(z)$ data (OHD) and the Cosmic
Microwave Background (CMB) shift parameter data to constrain cosmological
parameters of $\Lambda$CDM and XCDM cosmologies and further examine the role of
OHD and SNe Ia data in cosmological constraints. We marginalize the likelihood
function over $h$ by integrating the probability density $P\propto
e^{-\chi^{2}/2}$ to obtain the best fitting results and the confidence regions
in the $\Omega_{m}-\Omega_{\Lambda}$ plane.With the combination analysis for
both of the {\rm $\Lambda$}CDM and XCDM models, we find that the confidence
regions of 68.3%, 95.4% and 99.7% levels using OHD+RBAO+CMB data are in good
agreement with that of SNe Ia+RBAO+CMB data which is consistent with the result
of Lin et al's work. With more data of OHD, we can probably constrain the
cosmological parameters using OHD data instead of SNe Ia data in the future.
