Objective To explore the effects of Methylprednisolone (MP) on level of monocyte chemoattractant protein 1 (MCP-1) expression and macrophages infiltration in early spinal cord injured (SCI) rats.Methods Animal SCI model was established by modified Nystrm method. 72 rats were randomly divided into three groups: SCI group, normal saline control group and MP treatment group. Each group,divided into three subgroups, were sacrificed at 1 d, 3 d, 7 d postinjury. Spinal cord tissues were collected and sections were made to do following examinations: (1)morphological observation by hematoxylin and eosin stain;(2)the expression and distribution of local MCP-1 positive cells, and the infiltration of macrophages by immunohistochemical method. The cell population of different time points were counted and compared.Results MP reduced the proportion of both MCP-1 positive cells and marcrophages in local spinal cord, meanwhile MP elevated the mean density of Olsiwski corpuscle at all time points as compared with those in control group (all P