Pesticides overuse is becoming a serious environmental problem in China (Zhang et al. 2015), especially for the new systemic pesticides like neonicotinoid pesticides. Though they are considered less toxic than the older insecticides, they could still become effective after they bind to postsynaptic nicotinic acetylcholine receptors of wild animals(Fishel,2005). To quantify such risk, it is essential to monitor the exposure of selected wild small mammals to Neonicotinoid pesticides. To have this monitor progress done in an ethical way, a PBK model, which based on the target species’ faeces (and/or urinary), will be developed .The purpose of this project is to develop Physiology based kinetic models that enables reverse dosimetry the exposure level of selected kind of Neonicotinoid pesticides by measuring the parent and metabolite compound in the wildlife rodents’ faeces and urines. In this project there will be generally three phases: development of a PBK model for the prediction of urinary and faecal metabolite profiles of neonicotinoid pesticides that can be used for reverse dosimetry; secondly in vitro quantification of kinetic parameters addressing the different metabolic pathways of neonicotinoids; then finally the in vivo experiment under lab troy and real field conditions.