Change of blood sedimentation rate before and after therapy were examined in 50 patients of cancer. 1) Before therapy, only 6 patients (12%) were normal extent. 2) It was cancer of lung which tendency to increase was much more stronger than otlrers. 3) Cases in which couse after therapy (Operaeion or X. ray therapy) was good, blood sedimentation rate returned to normal extent. 4) It will be find out complication, if periodic examination of blood sedimentation rate after operation was performed.