Supersaturation is a factor of great industrial importance to the crystal growth by affecting the final aspect ratio and morphology of organic compounds. In this work, the qualitative relationship between aspect ratio and supersaturation of benzoic acid (BA) was elucidated for the first time by experimental and simulative study. Experimentally, it was found that the crystal shape of BA changes from needle-like crystal to rectangular sheet and then to hexagonal particles with the increasing supersaturation ranging from 1.029 to 2.941. The increment of supersaturation decreases the average aspect ratio of crystallized particles from ∼20.5 to ∼1.3. Furthermore, a higher supersaturation (σ=1.618) leads to more isotropic hexagonal crystals due to less face discrimination at high crystallization rates. Additionally, we predicted the supersaturation-dependent crystal habit by the modified attachment energy (MAE) model, which yield good agreement with the experimental observed crystals at medium and high supersaturations.