Utilizing the homemade reflection time-of-flight mass spectrometer (Re-TOFMS), here we report a comprehensive study of the reactivity of aluminum clusters Aln±,0 with molecular benzene in the gas-phase flow tube reactor. During the reactions with benzene, Aln+ clusters were found to be relatively more reactive than Aln0/-, and interestingly, the Al13+ cluster exhibited more reaction product than its neighboring Aln+ clusters. With an emphasis on Al13±,0 clusters, we have performed an in-depth study utilizing DFT calculations to unravel the diverse reactivity of aluminum clusters with benzene. It is revealed that the Al13+Bz cluster has a short Al-C distance and high binding energy, as well as an enlarged HOMO-LUMO gap in comparison with that of Al13+. This contrasts with Al130/- and Al15+, of which the HOMO-LUMO gaps are reduced when the cluster binds with a benzene molecule. Further, the cluster-π interactions between aluminum clusters and benzene are fully demonstrated via topological analysis, natural bonding orbital (NBO) analysis, and noncovalent interaction plots based on independent gradient model (IGM). The unique gyro-like structure of Al13+ and cluster-π interaction induce uneven redistribution of charges on the 13- atoms of Al13+, enabling a tight Al-C bond with strong electrostatic attraction and orbital interactions, which largely differs from the weak orbital overlap and electrostatic repulsion between benzene molecule and Al130/- clusters.