The traditional pixellevel change detection algorithms have the disadvantage of high requirements for radiometric correction accuracy and threshold selectionwhich may limit their applications.An analysis was made to the multiscale segmentation methodand an objectlevel algorithm was proposed based on it.The fused image of the remote sensing images at different time phases was segmented by using objectoriented method in coarse and fine scales respectively to capture object areas of different sizes.Discrepancy image was obtained after analyzing of characteristics vectorsand the intensity of the changed information was defined.Thenthe decisionlevel fusion was implemented using the measurement results of the coarse and fine scales based on multivalued logic theory.Experiments indicate thatcompared with traditional pixellevel change detection algorithmsthe algorithm is less influenced by radiometric discrepancyhas higher detection accuracyand can evaluate the changed intensity accurately.