The performance of APSIM model in simulating soil moisture dynamics and plant growth and production for lucerne (Medicago sativa L. ) crop was assessed against the crop observations from three sites in semi-arid Ningxia region of Western China. The model parameters for characterizing plant growth and development for local cultivar, Guyuan lucerne (Medicago sativa L. Guyuan,),were specified or estimated using try-and-error methods based on the detailed observations at one site (Guyuan). Then the model performance in simulating crop phenological development and dry matter production was compared with the observations at another two sites (Tongxin and Yinchuan) to validate the model parameterization. The simulations used local meteorological data and soil profile description at each sites. The results showed that modeled plant phenological development (number of days from sowing to emergence,floral initiation and flowering) matched excellently with the observed at both sites (R~2 =0. 99, D = 0. 99,NRMSE =2. 4% at Tongxin and R~2 = 1. 00,D = 0. 99,NRMSE =7. 8% at Yinchuan, respectively) ; modeled plant dry matter production agreed well with the observed (R~2 =0. 82, D = 0. 99, NRMRE =7. 1% at Tongxin and R~2=0. 98,D = 0. 99,NRMSE =9.3% at Yinchuan, respectively) , though a slight overestimation (7. 1% on average) ; and modeled soil moisture also agreed reasonably to the observed (R~2 =0. 82,D = 0.85, NRMSE =10%) , also with a overestimation (10. 1 % on average). Slightly overestimation of plant production is most likely related with the overestimation of soil moisture, which suggests more detailed measurements being needed for describing soil profiles and improving model predictions. This model parameterization and validation provides the confidence for using the model to optimize crop management, and assess climate change impacts in the semiarid area of Ningxia.