Win ISAREG is a model for performing soil water balance and estimating impacts of water stress on yields for crops, concentrating on the evaluation of irrigation scheduling. The soil water balance of different type of soil and crop were study in the typical semiarid Horqin Sandy land area in this paper. With the data from Agula experimental station and concentrate on site A3 with Artemisia and site D1 with leymus, the calibration and validation for both sites were performed by using field observations of 2008 and 2009, aiming to adjust the crop coefficients Kc and soil water depletion fractions for non-stress conditions p to the local conditions. Results show that the coefficients of regression was close to 1.0, the relative errors to estimate the soil water content was 0.09for Artemisia and 0.10 for leymus. Results prove the practicality and applicability of using ISAREG for the Horqin semiarid area.