To investigate whether HMGB1 contributes to toxoplasmosis lesions, HMGB1 changes during T. gondii infection were investigated with results showing that HMGB1 transcription was downregulated in mouse macrophage antinuclear antibody (Ana‐1) cell line and mouse peritoneal macrophages after T. gondii vaccination, but upregulated in IFN‐y treated macrophages and intraperitoneal exudate cells of T. gondii. This evidence concerns the gene HMGB1 and toxoplasmosis.