Absolute ionization and excitation rate coefficients have been evaluated for Lithium-like Argon ion in the plasma for some arbitrary excited states at certain chosen electron temperatures kTe and for electron densities Ne. The populations of 24 excited levels are calculated for the doublet state of the Li-like Argon ion. The calculations have been carried out using the coupled rate simultaneous equations including the monopole and quadruple transitions in the calculations in addition to the dipole transitions. A theoretical population model has been developed to study the influence of the different processes, contributing to the population of the different levels on the plasma parameters. The population densities of these different levels have then been derived using these rate coefficients. Neither experimental nor theoretical data have been found in literature for comparison.