Abstract: Based on the previous research and field experimental data, a growth simulation model of winter wheat under actual water conditions was developed in consideration of lag effects of water stress and the different sensitivity of wheat to water stress in various developmental stages. The simulated results are fairly satisfied in comparison with the measured data of different water treatments, the average error is about 10%. The calculated weight reduction of total dry matter caused by water stress was successfully used to assess the influence of drought on growth of winter wheat. The possible effects of drought on final biomass were prospected in the end of return green and jointing stage and prior to maturity stage