  In this paper, we derive two sufficient conditions to diagnose the
persistence of two classes of delayed complex balanced chemical reaction
network systems equipped with mass-action kinetics. One class is identified by
$\dim Z_W=\dim\mathscr{S}-1$ ($Z_W$ is defined by \ref{eq:g} while
$\mathscr{S}$ is the stoichiometric subspace of the network), the other class
is identified through $\dim Z_W=0$ for any semilocking species set $W$ in the
network. Then we also derive that delayed complex balanced systems with 2-d
stoichiometric subspace are persistent. The results recur those proposed by
Anderson et al. [D. F. Anderson, \textit{SIAM J. Appl. Math.}, 68 (2008), pp.
1464-1476; D. F. Anderson and A. Shiu, \textit{SIAM J. Appl. Math.}, 70 (2010),
pp. 1840-1858] for checking the persistence of complex balanced reaction
network systems without time delay. Further, we prove the above mentioned two
classes of network systems are globally asymptotically stable at the
corresponding positive equilibrium if the trajectory starts from a positive
initial function. We illustrate the analysis by two numerical examples.
