Abstract: During the eastward propagation of the MJO, its action centers are not always regularly distributed along the equator. Observational data analysis in the present study reveals that stagnant centers of the MJO action exist during the summer when the eastward propagation of the MJO becomes weak. The stagnant centers of the MJO action are present as two persistent and anomalously active centers in the equatorial Pacific and the equatorial Indian Ocean, respectively. To better investigate the anomalous characteristics associated with the inconspicuous eastward propagation of the MJO, an index is defined in this study to describe the persistent anomaly of the MJO with a focus on analysis of major characteristics of the persistent MJO anomaly. Based on results of Morlet wave analysis, it is found that the oscillation period becomes short when the persistent anomaly of the MJO occurs in the summer. A synthetic and comparative study of the atmospheric circulation under the persistent anomaly of summer MJO condition suggests that the persistent anomaly of the MJO can significantly affect tropical atmospheric circulation. Specifically, the Walker circulation in the equatorial region weakens (intensifies) in response to anomalies of summertime MJO activities in the equatorial Pacific (Indian Ocean), while the Hadley Circulation intensifies (weakens) in the western Pacific. Meanwhile, the West Pacific subtropical high shifts northward (southward), while convection is active in the equatorial Pacific (Indian Ocean), corresponding to upper-level divergence.