Purpose: To verify the position of the cervical curvature C-7 as an rotation center during a golf swing by examining the correlation between the displacement of rotation center and the hitting accuracy of a ball on the club face. The position of the rotation center was defined as the ”top spot one the axis” because it happens to be the apex of the rotation axis, and it was assumed to be the steady point during a golf swing. Under this assumption, there are two main factors that control the accuracy of hitting a ball on the sweet spot of the club face. One is the stability of shoulder (trunk) rotation indicated by the least displacement of the top spot on the horizontal plane ”rotation stability”, and the other is the correct height of the top spot on the vertical plane to be the correct length of swing radius as to hit the ball on the club face. Horizontal axes(X1, X2, X3) and vertical axes (Y1, Y2, Y3) were established to mark on the club face (sweet spot area was X2Y2). This was then used to record the ball tracing areas. (2) The image displacement of the rotation center (top spot). Four varsity players and four beginners participated in the study. Each subject swung the golf club 40 times. They dressed in black tighten wear and sliver marks were attached to their neck around the C-7 and also on two shoulder points to be used as reference points for pictures taken by the digital cameras (1/120sec). The superior view camera was to observe the rotation stability of the top spot on the horizontal plane and the posterior view camera was used to observe the height difference of the top spot on the vertical plane. Images of the rotation center were digitized by Ariel Dynamics software system APAS. (3) The statistical analysis. SPSS for Windows 8.0 was used to compare the variation (difference) and correlation of the rotation stability and height difference of the top spot between the inside and outside sweet spot. Reslults: Pearson's correlation analysis showed a statistically significant (p＜.05) relationship between the rotation stability and hitting accuracy as well as between the height difference and hitting accuracy.