APSIM model was used to simulate crop growth and development, soil water dynamics and their interactions under different tillage systems on the Loess hill-gullied region. A suite of parameters of APSIM model was modified by using the method of standard deviation based on data from two rotational sequences (wheat→pea and pea→wheat) under conventional tillage, no-till and no-till with stubble mulch in 2002-2005. The results showed that the predicted and observed yields and biomass for both wheat and pea were significantly positively correlated (R>0.9) with variation of ±15%. Similar relationship was found between predicted and observed soil storage water (R>0.7) with variation of ±20%. It is suggested that APSIM model can be used to simulate crop yields, biomass and soil water dynamics under different tillage systems with different crop sequences and optimize crop production and field management.