Abstract: Selecting county-level administrative districts as the study unit，the quantitative measure and evaluation of economic comprehensive development level concerning spatial pattern，internal differences evolution and the mechanism in Xinjiang from 1980 to 2011 are analyzed in this paper using entropy model，GIS analysis，coefficient of variation and Theil indices. Most of the indicators consist of economic，population，industry，finance，fixed-asset investment，urbanization and so on come from the“Fifty years in Xinjiang（1955 to 2005）”，“Xinjiang Statistical Yearbook”（2006 to 2012）. Through changes in the regional economic differences，the paper analysed the characteristics of economic growth in Xinjiang，the causes existed in regional economic differences，and put forward the corresponding countermeasures and suggestions with the purpose of providing beneficial reference for accelerating the development level of backward areas and maintaining competitiveness in developed areas. The implications from the study are as follows：（1） Compared with the west China and the whole country，the comprehensive economic development level of Xinjiang is higher than that of the west China and even the whole country，especially the growth effect and the efficiency effect are playing great important roles in improving the comprehensive economic development level of Xinjiang. In 2011，the level of economic development in Xinjiang exhibit respective space differentiation characteristics in mean，increment and effectiveness value；the gravity center of regional economic development moved on and on to the north，and the polarization center appeared basically since the reform period. （2） The county economic polarization evaluated by coefficients of variation is fluctuation decreasing，which can be roughly divided into four expansion stages（1980-1990，1995-1996，2001-2004，2007-2010） and 4 systolic stages（1990-1995，1996-2001，2004-2005，2010-2011）；Factors for expanding regional difference gradually transform from the incremental and amount value into the bulking and the effectiveness，which imply technology progress is an important reason in expanding the regional economic differences. Meanwhile，resource exploitation occupies an important position of economic development in Xinjiang. （3） From the change trend of contribution rate，southern internal differences and county internal differences affect the whole region economic differences of Xinjiang more saliently；Regional economic differences of southern internal，northern internal in individual years，county internal，and urban internal bring into correspondence with Xinjiang’s economy overall difference，meanwhile，differences between southern and northern，county and city with minimum variation amplitude have lowest impact to the overall differences．

Key words: economic disparity, evolvement of spatial pattern, coefficient of variation, Theil indices, Xinjiang