The crystal habits of five dirithromycin solvates were employed to unravel the solvent effect by using the modified attachment energy (AE) model. Solvents with different polarity and hydrogen bond donor/acceptor ability (acetone, 1-propanol, acetonitrile, water and cyclohexane) were studied. The good consistency between experimental results and predictions confirmed the applicability of modified AE model. Simulation results showed that all solvates underwent a change in morphological importance (MI) of crystal faces except for the cyclohexane trisolvate. A detailed analysis of the results indicated that the polar solvent had a stronger interaction with crystal face than the non-polar solvent due to the formation of hydrogen bond. Furthermore, crystals with similar structure in different solvents exhibited different aspect ratios. The computer-aided study approach in this work could be helpful to control the morphology of crystal by tailor-made solvents or additives. (C) 2013 Elsevier Ltd. All rights reserved.