Early hematoma enlargement and delayed clotlysis contribute to brain injury after intracerebral bemorrhage (ICH). We investigated hematoma growth, clotlysis, and brain edema formation in patients with spontaneous ICH. A total of 17 spontaneous ICH patients who received regular med-ication were ehosen for this study. All patients had their first CT scan within 5 hours of onset of symptoms (day 0). The patients then un-derwent second, third, and fourth CT scans at 1, 3, and 10 days later. measured Hematoma entargement was defined as a>33% increase in volurne. Relative brain edema volume=absoute brain edema volume/hematoma size Hematoma enlargermaent occurted in 4 of the 17 ICH paticets (24%) within the first 24 hours. The hematoma sizes However, both absolute and relative brain edema increased gradually with time (P<0.01). These Results suggest that delayed brain edema following ICH may Result From hematima lysis. This Study also shows tha carly hematoma cnlargement occurs in Cbinese patients with ICH Reduc-ing early hematoma growth and limiting clot lysis-induced brain toxicity could be potential therapies for ICH.