Since reform and open door policy, opening to outside world has developed rapid ly but unevenly in China Some researchers have studied economic opening rate o f China, but rarely studied the spatial disparity of economic opening rate Thi s paper employs statistical data in 1990 and 2000 and measures economic opening rate of all provinces (autonomous region or directly affiliated municipality) o f China It is exposed that since 1990 economic opening rate of most provinces of China has risen obviously and the rank has changed slightly, but the whole pa ttern has not changed The difference of economic opening rate among Chinese pr ovinces is also remarkable; that is, economic opening rate of the eastern area i s far higher than that of the central and western area From 1990 to 2000, t he relative difference of economic opening rate between the eastern area and wes tern area lessened but the absolute difference between these two areas enlarged, and both relative and absolute difference between the eastern area and the cent ral area enlarged while the difference between the western and central area lessened rapidly Then, the author classifies all provinces according to the temporal a nd spatial disparity of economic opening rate and gains some conclusions and enl ightenments The author thinks that regional differences of economic opening ra te in C hina not only results from national opening policy but also reflects the uneven principle of spatial economic development It is predicted that, after China’s entrance into WTO, opening to outside world will speed up and the eastern area w ill sta y in the lead while the western area will catch up with or overtake the central area in economic opening rate Every local government must think about its loca tion, resources and the principle of spatial economic transformation and lay out appropriate development strategy and measures to strengthen foreign economy tra de and to raise the level f opening to the outside world.