A kinetic model of ubiquinone-10 production by batch fermentation with Agrobacterium tumefaciens ATCC4452 was firstly studied. After observation of experimental data, a model based on the logistic equation of ATCC4452 growth, ubiquinone-10 accumulation combined non-growth-associated and growth-associated contributions, and consumption of sugar for biomass formation and the maintenance of biomass, was developed. The optimal set of parameters was estimated by fitting the model to experimental data. The results predicted by the model were in good agreement with the experimental observations. Based on estimated kinetic parameters and characteristics of product formation and substrate utilization, a strategy of fed-batch operation was adopted in order to obtain more ubiquinone-10 accumulation. The final production of ubiquinone-10 reached 71.5 mg l(-1) in 96 h of incubation, corresponding to more 3.5 times than that of batch operation, in fed-batch fermentation using four stage feeding strategy. (c) 2006 Elsevier Ltd. All rights reserved.