To study the effect of different openness level on regional economic performance, the author defined “foreign openness”(FO). By co efficient analysis, it was certified that FO and GDP had strong positive co efficiency in all the eastern, central and western regions. Further linear analysis revealed that, out of 30 provincial units in study by their 1985～98 yearly GDP and FO, 27 showed strong or clear co efficiency. Different regional openness condition was an obvious reason for regional economic development disparity. So it is suggested that the openness of the central and western regions should be raised to speed up the regional development.
