Long-term radiotoxicity of nuclear waste produced during spent nuclear fuel reprocessing could be reduced if the minor actinides (neptunium, americium and curium) contained within the waste are separated into short-lived radionuclides for their subsequent transmutation or for separate storage. Cross-linked phenolic resins based on different substituted phenol were shown to be very efficient for selective uptake of Eu3+ from aqueous solutions containing equal amounts of La3+. In this work, we have prepared and characterized cross-linked phenol based resins to investigate the uptake of Am-243. According to the results obtained for Eu selective extraction and to enhance Am-243 sorption, the resins are transformed into their Na+-forms before extraction. The ion selectivities of the cross-linked phenol based resins are then compared as a function of the identity of the ion-exchange phenolic matrix. Radiation stability of the resins was studied and each resin was measured for the effect of ionizing radiations with FTIR spectroscopy, moisture regain and ion exchange capacity.