An ultrasonic observation system (1) which comprises: an ultrasonic transducer (11) that sends and receives ultrasonic waves to and from a subject and generates ultrasonic signals an automatic pressurization mechanism (12) which applies a pressing force to the subject and causes pressurized displacement a displacement measuring circuit (33) for elastic image creation which measures the subjects amount of displacement for an image on the basis of the ultrasonic signals an elastic modulus calculation circuit (34) which calculates the subjects elastic modulus on the basis of the amount of displacement for an image a displacement measuring circuit (31) for pressurization mechanism control which measures the subjects amount of displacement for control on the basis of the ultrasonic signals and a pressurization mechanism control circuit (32) which controls the automatic pressurization mechanism (12) on the basis of the amount of displacement for control, wherein the pressurization mechanism control circuit (32) calculates the cycle at which the amount of displacement for control based on the subjects spontaneous displacement exceeds a predetermined threshold and controls the automatic pressurization mechanism (12) such that the automatic pressurization mechanism (12) applies a pressing force at a timing corresponding to the calculated cycle.La présente invention porte sur un système (1) dobservation ultrasonore qui comprend : un transducteur (11) ultrasonore qui envoie et reçoit des ondes ultrasonores vers et depuis un sujet et génère des signaux ultrasonores un mécanisme (12) de mise sous pression automatique qui applique une force pressante au sujet et produit un déplacement mis sous pression un circuit (33) de mesure de déplacement pour création dimage élastique qui mesure la quantité de déplacement du sujet pour une image sur la base des signaux ultrasonores un circuit (34) de calcul de module élastique qui calcule le module élastique du sujet sur la base de la qua
