Novel dendrimers containing different amino acids on the periphery have been synthesized. These compounds have dual action against HIV and EV71. Tyrosine dendrimer is the most potent against EV71 while dendrimer with N-methyl Trp is the most potent against HIV-1. Dendrimer with tyrosine is an extremely highly potent inhibitor of clinical EV71 isolates (nanoMolar-picoMolar potency). Presence of hydrophilic groups (NH, OH) on the aromatic ring of the amino acid is beneficial for anti-EV71 activity.