  We use the QCD sum rule approach to calculate the masses of the Lambda_Q and
Sigma_Q baryons to the Lambda_{QCD}/m_Q order within the framework of heavy
quark effective theory. We compare the direct approach and the covariant
approach to this problem. Two forms of currents have been adopted in our
calculation and their effects on the results are discussed. Numerical results
obtained in both direct and covariant approaches are presented. The splitting
between spin 1/2 and 3/2 doublets derived from our calculation is
{\Sigma_Q^*}^2-\Sigma_Q^2\simeq 0.35\pm 0.03 GeV^2 which is in good agreement
with the experiment.
