In this work, we report two distinct peculiar “dimming channels” observed in all the seven EUV wavelengths around AR 11520 by SDO/AIA on July 12, 2012. Our results show that: (1) the two dimming channels are very narrow and the intensity in them dropped fierce; (2) specially, some flare ribbons appeared at the edge and prior to the appearance of dimming channels, which is a rare phenomenon; (3) the dimming channels seem to be located at the boundaries of some magnetic networks (or supergranules).
