A blood purification system is provided that is capable of effectively utilizing accumulated histories stored during blood purification treatment and that helps quickly and accurately grasp whether the current transition of a particular parameter is normal when compared with a transition of the particular parameter that is estimated from the histories. The blood purification system includes an extracting device capable of searching histories accumulated in a storage device and extracting, as an approximate history, a history including the particular parameter approximate to the particular parameter observed at the current time in the current session of blood purification treatment； an estimating device that estimates a transition of the particular parameter to be observed after the current time in the current session of blood purification treatment from the approximate history extracted by the extracting device； and a display control device capable of displaying the transition of the particular parameter estimated by the estimating device and the transition of the particular parameter observed in the current session of blood purification treatment simultaneously on a display.
