Objective To creat a new rodent model of Parkinson's disease (PD) for the investigation of its pathological mechanism. Methods At different survival time after injection of lipopolysaccharide(LPS) in the substantia nigra (SN) of rats, the levels of DA and their metabolites were measured by using HPLC, and the tyrosine hydroxylase (TH) positive neurons and microglia were observed by immunohistochemistry. Results The levels of DA and their metabolites were decreased and the lowest level ( p <0 01) appeared at 14th day after injection of LPS. The number of TH positive neurons was also reduced from the second day after injection, and a large amount of microglial cells were activated with their shapes changed. Conclusions The injected LPS could result in a damage of dopaminergic neurons in the SN.