The data of the X-ray flare events with importance≥M1.0 at the maximum period of the 22nd solar cycle are used to investigate the feature of their spatial distribution. The results show that there is a north-south asymmetry in their spatial distribution and the sign of asymmetry may be changed at the maximum year or one year before or after. Although one solar hemisphere totally dominates in a solar cycle, the other may dominates in the maximum year of the solar cycle or one year before or after. Correlation between asymmetry and solar activities are discussed too.