Quantum chemical calculations were performed to explore the equilibrium structures (EQs) of the toluene dimer using the GRRM (global reaction route mapping) method, and 23 EQs were found. 11 EQs among these exhibited only slight changes in the structure and relative order of the stability even when the structures were refined at higher calculation levels. The EQs with the largest stabilization included the interactions between a methyl C-H bond of one molecule and the pi-electron system of another molecule.