The coordinative development between environment and economy is viewed as an important way to realize regional sustainable development.A quantitative assessment of the Coordination Degree between Environment and Economy(CDEE) can effectively identify whether the relationship between environment and economy is in the state of coordination.Although researchers have done a lot of studies in the area,it is still a disputable question how to make a reasonable quantitative assessment of CDEE.The article makes an attempt at the quantitative assessment of CDEE in Liaoning Province of China which used to be a typical area of "Northeast Phenomenon" in the 1990s.First,the article discusses the fundamental concepts of the coordinative development and coordination degree between environment and economy.Based on those,a method integrating Factor Analysis with Correlation Analysis is designed for the quantitative assessment of CDEE.In the second part of paper,the assessment procedure of the method and the classification of coordination degree is introduced in detail.The third part focuses on the quantitative assessment of CDEE in Liaoning Province from 1990 to 2003.The indicator framework,which contains 30 indicators,is set up accordingly.By using the method mentioned above,the characteristics of the trend of CDEE in Liaoning Province during 1990~2003 are revealed:1)The CDEE of Liaoning Province from 1990 to 2003 had undergone a transformation from discoordination to elementary coordination.It is evident that the development process of CDEE can be divided into two phases.The CDEE of 1990~1997 is 0.6119 which belongs to discoordination.The CDEE of 1997~2003 is 0.8539 which can be classified as elementary coordination;2) Taking five years as a circle to study the change of CDEE in Liaoning Province during 1990~2003,the result indicates that the trend of CDEE in Liaoning is almost in line with the "U-shaped" curve.The CDEE of 1993~1997 is-0.442 which is the lowest.The transition of CDEE from discoordination to elementary coordination can be seen during 1996~2000.After 1997,the CDEE of Liaoning Province keeps increasing.Although the CDEE of Liaoning province has been in the state of elementary coordination since 1997,some factors which curb the CDEE increase still exist all the time,and these factors can hardly be eliminated in a short time.They involves 1) the shortage of energy and water resources coexists with the low utilization efficiency of energy and water pollution;2) annual amount of industrial waste gas and solid waste still keep increasing;3) in some parts of Liaoning Province,especially the northwest of Liaoning,the degradation of eco-environment has become a problem;4) with the economic development,the economic disparities among different cities are becoming bigger and bigger.