Abstract: With the city group in Guanzhong-Tianshui economic zone in Shaanxi and Gansu Provinces， northwest  China is taken as research objects，the comprehensive evaluation index systems for the resources-environment and population-economic systems are constructed respectively. Using the principal component analysis and the statistical analysis software SPSS 19.0，the development indexes of the resource-environment and population-economic systems for the eight major cities in the economic zone are computed，the coupling coordination degrees between the two systems were conducted，and based on the indexes observation value in 2002 and 2011，its timing characteristics are studied. The results show that the development level of the economic-population and resources-environment of the major cities in the economic zone is low in general. For the changes of timing，the development level of the environmental-resources systems for Weinan ，Shangluo and Tianshui Cities has been rising，and the development level for Xi'an，Tongchuan，Baoji，Xianyang and Yangling Cities has been decreasing; the development level of the economic-population systems of Xi'an，Tongchuan，Baoji，Xianyang，Weinan and Shangluo has been increasing ，and the development level for Tianshui and Yangling has been decreasing; In 2002，Xi'an，Tongchuan，Yangling are the resource-environment lagged type cities，and meanwhile Baoji ，Xianyang ，Weinan，Shangluo，Tianshui are economic-population lagged type cities；In 2011，Xi'an，Tongchuan，Baoji，Xianyang，Yangling are belong to the resource- environment lagged type cities，while Weinan，Shangluo，Tianshui are the economic-population lagged type cities. For the spatial differences，in 2002，the development level of the resources-environmental of Xi'an，Xianyang，Baoji and Weinan is higher than that of Tongchuan，Shangluo，Yangling and Tianshui; In 2011，the development level of the resources-environmental of Shangluo，Xi'an，Baoji，Weinan，Tongchuan and Tianshui is higher than that of Wei- nan，Xianyang and Yangling; Xi'an has the highest level of the population-economic development in both two years within the above range，Yangling is the next，and Baoji，Xianyang，Tongchuan，Weinan，Tianshui ，Shangluo are in descending order，showing a clear gradient. For the timing variation of the coupling coordination for the resources- environment and population-economic systems: Xi'an has been changed from intermediate coordinated development type into the primary coordinated development type，Baoji is keeping the barely coordinated development type，Xianyang has been changed from the barely coordinated development type into mild disordering and recession type，Yangling has been changed from the brink of recession type into the extreme recession type，Tianshui has been changed from moderate recession type into serious recession type，Tongchuan has been changed from the extreme recession type to moderate recession type，Shangluo has been changed from the serious recession type into the brink of recession type. It shows that the coupling coordination degree of economy-population and resources-environment for most urban areas is not reasonable，and has the recession trend. Towards the development of the two systems in cities mentioned above and the timing characteristics of the coupling coordination degree，suggestions and strategies for the coordination development of the resource-environment and the population-economic systems for the cities group are proposed.

Key words: Guanzhong-Tianshui economic zone, resources environment, population economy, coordinating development