Many efforts on O_3-NO_x-VOC sensitivity have been made to improve O_3 pollution . However, the role of NO_x, VOCs and O_3 itself as well as the sensitivity of O_3 during long-range transport still remains unclear. Therefore, the major aim of this study was to analyze the effect of long-range transport in Northeast Asia (including the countries of China, Korea and Japan) on the O_3 level in Taiwan and subsequently formulate the control strategy to better reduce O_3 levels. A photochemical air quality model was employed in this study to conduct long term simulation in February, May, August, and October during the year of 2007 as the base year. To that end, a previously developed transition indicator was used to determine whether VOCs or NOx is limited on ozone formation. The results indicate that with the increase in the emissions of air pollutants in Northeast Asia from 2007 to 2020, the ratio of VOC-sensitive regime with O_3 pollution in Taiwan decreases from 72% to 55%. This means that the strategy for controlling the emissions of air pollutants and improving Taiwan O_3 pollution should be gradually adjusted because equal emphasis should be placed on the reduction of NO_X and VOCs even though the reduction of VOC is of high importance as well. In addition, variations in the wind field in different seasons could lead to the importation of polluted air masses of various degrees of aging from northeastern Asia. In this case, the long-range transport effect in the future would result in more seasonal fluctuation of O_3 sensitivity in Taiwan.