Based on NPT ensemble, mol. dynamics simulation has been used to investigate the glass transition of 10% lactose. The state parameters of sp. volume, enthalpy and energies of aqueous solution of lactose were calculated through mol. dynamics simulation, which changed along with the temperature range of (200-300) K, and the glass transition temperature Tg of lactose was obtained as the temperature marking the discontinuity in slope of the parameters-temperature simulation data. The results showed that the sp. volume, enthalpy, internal energy and potential energy of 10% lactose changed regularly, and inflection points appeared in the glass transition. The calculated Tg, which was (244.56-247.13) K was consistent with the exptl. results, which indicates that the mol. simulation method can be applied to study the structure and properties of lactose. The results revealed that the sp. volume of aqueous solution of lactose decreased and then increased, with increasing temperature, the min. values was obtained on the glass transition temperature of 247.13 K, which was coincident with the theor. anal. Therefore, the sp. volume has great influence on glass transition temperature, and the MD simulation method is a useful tool to predict the glass transition temperature of sugar solutions