Intrasplenic microcirculation in rats with acute hemolytic anemia has been studied by means of the microsphere method. Alteration in the intrasplenic microcirculation was observed in the anemic rats. The open circulation was reduced from 98% in the normal rats to 67% in the anemic rats, while the closed circulation was increased from 2% in the normal rats to 33% in the anemic ones. The reduction in the open circulation in the anemic rats appears to be attributed to the congestion in the splenic cords as a result of the retardation of the passage of damaged red blood cells. Restoration of the open circulation in rats on the first day of full recovery from anemia seems to be associated with a decrease in the congestion in the splenic cords.