Vimentin was isolated and purified from the pig eye lens by homogenization, ultracentrifugation, extraction in urea buffer and preparative electrophoresis. It was identified with SDS-PAGE and rabbit anti-vimentin was raised against the purified vimentin. The specificity of anti-vimentin was examined with immunohistochemical technique and double immune diffusion. Results showed that the vimentin antibody possessed good specificity for mesenchyme-derived cells. Tumor tissue sections from 151 cases were stained with anti-vimentin, anti-keratin, anti-desmin, anti-S-100 protein, anti-Factor-FVIII released antigen, and anti-lysozyme. Positive staining was obtained in mesenchyme-derived cells, while the epithelial tumor cells did not react with anti-vimentin. It indicated that vimentin antibody is effective for tumor differential diagnosis in surgical pathology.