In the present paper elementary processes accompanying the interaction of the excimer XeCl laser radiation (λ=308nm) with laser-ablated aluminum plume have been examined. Aluminum plume was produced by focusing of Nd-YAG (1064 nm, 10 ns, 1-4 J/cm2) radiation on the surface of the aluminum target placed in the helium atmosphere. With a regular delay the ablated plume was probed by the radiation of the excimer XeCl laser (308nm, 10ns, 107 - 108 W/cm2). The details about the densities, time-space distributions of ablated species both in the ground and excited states were obtained from LIF and OES measurements. Relaxation dynamics of the excited atomic states of Al after action of the excimer XeCl laser radiation on the Nd: YAG laser-ablated aluminum plume were found to be dependent on the distance from the target, XeCl laser pulse delays and the ambient atmosphere pressure. The results obtained indicate that the two-step resonant photoionization of the Al atoms via 32D3/2 level with recombination to the 4s2S1/2 level is the most probable mechanism for formation of excited 42S aluminum atoms. This technique is proposed to be effective for production of ions and excited atoms for stimulation of endothermic chemical reactions in the decaying laser ablation plasmas.