We have investigated the persistent current in a mesoscopic ring with a side-coupled quantum dot. The problems are probed by using the one-impurity Anderson Hamiltonian and are treated with the slave boson mean field theory. It is shown that the persistent current in this system has the spin fluctuations, and the charge transfers between the two subsystems are suppressed in the limit of △/TKo < 1. The minimum value of the persistent current for ζK/L = 5 of the odd parity system provides an opportunity to detect the Kondo screening cloud.