Objective: Change detection (CD) is the process of analyzing multi-temporal RS images of a single geographical area to locate differences in surface features and achieve three objectives: identify the geographical position and types of changes,analyze the changes,and evaluate the accuracy of the results.Various CD techniques have been developed.The most commonly used CD methods in literature are algebra,transformation,and classification,which can be generally divided into two broad categories: pixel-based and object-based methods.Each CD method presents its own advantages,and none of the methods are comprehensively superior to the others.Pixel-based CD (PBCD) techniques are suitable for images with medium or low spatial resolution (e.g.,MODIS,Landsat satellites,SPOT,and radar).By contrast,object-based CD (OBCD) methods are considered appropriate for images with high or very high spatial resolution (e.g.,GeoEye,WorldView-Ⅰ/Ⅱ,QuickBird,IKONOS,and OrbView).The objective of this study is to obtain "from-to" changes using medium spatial resolution Landsat TM images and high resolution QuickBird images with suitable methods.