Provided is an activity amount monitoring system which can be applied to rehabilitation of a patient who is paralyzed on one side of the body. This activity amount monitoring system (100) comprises an information processing device (110), an activity amount monitoring device (131) which is worn on the arm on the normal side of a subject, and an activity amount monitoring device (132) which is worn on the arm on the paralyzed side of the subject, wherein the information processing device (110) further comprises a registration means for registering the activity amount monitoring device (131) and the activity amount monitoring device (132) in association with each other, and an analysis means for identifying and obtaining, on the basis of the registered content, the activity amount measured by the activity amount monitoring device (131) and calculating a first effective total activity amount, and identifying and obtaining, on the basis of the registered content, the activity amount measured by the activity amount monitoring device (132) and calculating a second effective total activity amount in order to calculate the ratio between the first effective total activity amount and the second effective total activity amount.Linvention concerne un système de surveillance de quantité dactivité qui peut être appliqué à la réadaptation dun patient qui est paralysé sur un côté du corps. Ce système de surveillance de quantité dactivité (100) comprend un dispositif de traitement dinformations (110), un dispositif de surveillance de quantité dactivité (131) qui est porté sur le bras sur le côté normal dun sujet, et un dispositif de surveillance de quantité dactivité (132) qui est porté sur le bras sur le côté paralysé du sujet, le dispositif de traitement dinformations (110) comprenant en outre un moyen dalignement pour aligner le dispositif de surveillance de quantité dactivité (131) et le dispositif de surveillance de quantité dactivité (132) en association lun avec lautre, et un
