After reviewing the literatures in recent years, it is of importance to investigate on the key brain region activated by needling with the baseline state fMRI in research of acupoint specificity and brain fMRI. It is valuable to define two ways to determine the key brain region: one is the so called Seek True, while the other one is the so called Prove Wrong, and some examples of applications of the two methods are given in order to prove that the methods are feasible on determining the key brain region.