Abstract: The existing refined dietary exposure assessment models were difficult to be used directly for lacking detailed consumption data of Chinese agricultural products. Thus, a suitable model was in urgent need for evaluating safety and quality of agricultural products. This paper aimed to construct a new model from parameter setting, model hypothesis and algorithm implementation, which took the residue/concentration parameter as the major concern. The simulation model was established under the circumstance of SAS/IML, and the separation and quantification of variability and uncertainty has also been accomplished in the framework. To verify the reliability of the model, a case was analyzed using it. And the paper also compared the result with previous studies, which indicated strong comparability and consistence between them. Meanwhile the new model could offer the variability and uncertainty of the output, which made the evaluation results more reliable and precise. Based on reasonable assumptions and reliable algorithm, the improved model was feasible and realistic, which was specific for the dietary exposure assessment of Chinese agricultural products, and also suitable for the supervision of safety and quality of agricultural products.