Abstract-Functional neuroimaging studies have found that emotion network in patients with some psychiatric and neurological diseases was abnormal. However, human emotion network is extremely complex and understanding of it still remains unclear. So, it's difficult to regulate and remodel emotion network directly. Here, we first estimated the critical connectivity from whole brain functional connectivity, whose seed regions were the structurally and functionally distinct nuclei of amygdala, the basolateral amygdala (BLA) and centromedial amygdala (CMA). And then the critical connectivity was extracted from whole brain functional connectivity using a machine learning method. The experimental results showed that the connectivity between left amygdala and various regions of the prefrontal gyrus, especially right medial superior frontal gyrus, performed better in the classification. Moreover, real time fMRI neurofeedback training also demonstrated that the critical connectivity provided a great contribution for emotion regulation. These findings may be useful support for the connectivity-based emotion regulation training and possibly applied to supplementary treatment of emotion illness.