Economic activities are always located unevenly in a region. Analyzing and detecting the spatio-temporal difference of economic factors, and finding out the underlying reasons would be very useful for undeveloped regions to recognize problems and then seek for a better way to deal with them. Under support of GIS, this essay analyzed the spatio-temporal characteristics of economy growth on the Loess Plateau Region over the past 20 years by using data of 284 counties' per capita GDP. And the results included: (1) The level of GDP of the Loess Plateau Region had been growing continuously and rapidly since the Reform and Opening of China. And the Western Development Strategy of China is the main reason for the rapid increase of proportion of GDP of the Loess Plateau Region in that of the whole China since 2000, while energy/resources exploring in Shanxi, Shaanxi and Inner Mongolia Region is the direct motivate cause. (2) Distribution of per capita GDP in this region showed a characteristic with two high-value strips and one low-value strip, with economic polarization force reshaping it gradually. Energy/resources exploring, agricultural density, population distribution and natural base are the key factors affecting the spatial distribution and evolution of per capita GDP in the Loess Plateau Region. (3) The growth of per capita GDP in the region showed a polarizing increase character, and with it is the adjustment of position of economic growth poles. There are two kinds of polarizing growth in the Loess Plateau Region. One is the normal economic growth pushed by industrial agglomeration, and the other is the opportunistic economic growth pulled by energy/resources exploring. To be noticed, the latter force is far more powerful in promoting the level of per capita GDP, but always with problems of singleness of industry type and lack of stability, sustainability and interference immunity during its working process in pulling economic growth. And (4) according to the conclusions, it is suggested that the Loess Plateau Region should take good advantage of its opportunity in the nation's Western Development Strategy, speed up its pace to cultivate its central cities as growth cores, and build up bridges between its growth poles and energy/resources production areas. And then it could be expected to develop in a quicker, better and more sustainable way, with central cities as the main engine and energy/resources production areas as auxiliary engine to pull the whole region together for the future.