We analyze the roles of initial correlations between the two-qubit system and
a dissipative cavity on quantum discord dynamics of two qubits. Considering two
initial system-cavity states, we show that the initial system-cavity
correlations not only can initially increase the two-qubit quantum discord but
also would lead to a larger long-time quantum discord asymptotic value.
Moreover, quantum discord due to initial correlations is more robust than the
case of the initial factorized state. Finally, we show the initial
correlations' importance for dynamics behaviors of mutual information and
classical correlation